All Calculators

BMI Calculator

Calculate your Body Mass Index (BMI) instantly from your height and weight.

Ideal & Healthy Weight Calculator

Estimate your ideal body weight based on your height, age, and gender using the Devine formula.

📏

Body Fat Percentage Calculator

Estimate your body fat percentage using the U.S. Navy circumference method.

💪

Lean Body Mass Calculator

Calculate your lean body mass (muscle, bone, organs) using the Boer formula.

🧍

Body Type Calculator

Estimate your somatotype (ectomorph, mesomorph, or endomorph) from your wrist size and height.

Waist-to-Hip Ratio Calculator

Calculate your waist-to-hip ratio (WHR) to assess health risk distribution.

Waist-to-Height Ratio Calculator

Calculate your waist-to-height ratio, a simple and reliable predictor of health risk.

🔥

Daily Calorie Calculator

Calculate your daily calorie needs based on your goal: lose, maintain, or gain weight.

BMR Calculator

Calculate your Basal Metabolic Rate — the calories your body burns at complete rest.

⚡

TDEE Calculator

Calculate your Total Daily Energy Expenditure based on your BMR and activity level.

🏃

Calories Burned Calculator

Estimate calories burned during exercise based on activity type, duration, and your weight.

Water Intake Calculator

Calculate your recommended daily water intake based on your body weight.

🏋️

One Rep Max Calculator

Estimate your one-repetition maximum (1RM) using the Epley formula.

❤️

Target Heart Rate Calculator

Calculate your ideal training heart rate zone using the Karvonen formula.

🏃‍♂️

Running Pace & Race Time Calculator

Calculate your running pace and predict race finish times for other distances.

🫁

VO2 Max Calculator

Estimate your VO2 max (cardiorespiratory fitness) using the Cooper 12-minute run test.

👣

Steps to Calories Calculator

Estimate how many calories you burn from your daily step count.

🍽️

Macro Calculator

Calculate your daily protein, carbohydrate, and fat targets based on your total calories and goal.

🥓

Keto Diet Calculator

Calculate your daily calorie and macro targets for a ketogenic (very low-carb, high-fat) diet.

🥩

Protein Intake Calculator

Calculate your recommended daily protein intake based on body weight and activity level.

🍞

Carbohydrate Intake Calculator

Calculate your recommended daily carbohydrate intake based on total calories.

🥑

Fat Intake Calculator

Calculate your recommended daily fat intake based on total calories.

⏳

Intermittent Fasting Calculator

Calculate your eating and fasting windows based on your preferred fasting schedule.

🧂

Sodium Intake Calculator

Check your daily sodium intake against recommended health guidelines.

🦴

Calcium Intake Calculator

Check your recommended daily calcium intake based on your age and gender.

Biological Age Calculator

Get a fun, educational estimate of your biological age based on lifestyle habits.

😴

Sleep Cycle Calculator

Calculate the best bedtime or wake-up time based on 90-minute sleep cycles.

🧘

Stress Level Test

A short self-assessment to reflect on your current stress level (not a clinical diagnosis).

💪

FFMI Calculator

Calculate your Fat-Free Mass Index (FFMI) to assess muscle mass relative to your height.

🎖️

Army Body Fat Calculator

Estimate body fat percentage using the U.S. Army circumference (tape test) method and compare it to standard limits.

🥾

Hiking Time Calculator

Estimate how long a hike will take based on distance, elevation gain, and pace using Naismith's Rule.

Cholesterol Calculator

Calculate your LDL cholesterol using the Friedewald equation and see your total cholesterol-to-HDL ratio.

Pregnancy & Motherhood Calculators — 10 tools

🤰

Pregnancy Calculator

Find out how many weeks and days pregnant you are, and your current trimester.

📅

Due Date Calculator

Estimate your baby's due date based on your last menstrual period.

IVF Due Date Calculator

Estimate your due date based on your embryo transfer date for IVF pregnancies.

💫

Conception Date Calculator

Estimate the date your baby was likely conceived.

🌸

Ovulation Calculator

Estimate your ovulation day and most fertile days based on your cycle.

Menstrual Cycle Calculator

Predict your upcoming period dates based on your cycle history.

Pregnancy Weight Gain Calculator

Check your recommended pregnancy weight gain range based on your pre-pregnancy BMI.

📏

Child Height Predictor Calculator

Estimate your child's likely adult height based on both parents' heights.

🧪

Pregnancy Test Calculator

Find the earliest date a pregnancy test is likely to give a reliable result, based on your last period, cycle length, or a known/estimated ovulation date.

Child Growth Percentile Calculator

Get an approximate estimate of where your child's weight or height falls compared to other children of the same age and sex, based on simplified WHO growth reference data.

Medical Calculators — 9 tools

🫘

GFR Calculator (Kidney Function)

Estimate your Glomerular Filtration Rate (eGFR) to check kidney function using the CKD-EPI 2021 equation.

BSA Calculator (Body Surface Area)

Calculate Body Surface Area (BSA) for medication dosing using the Mosteller or Haycock (pediatric) formula.

HbA1c Calculator (Average Blood Sugar)

Convert your HbA1c percentage into estimated average glucose (eAG) using the ADAG equation.

💓

Blood Pressure Calculator

Check your blood pressure classification (systolic/diastolic) based on the standard AHA guidelines.

💊

Weight-Based Dosage Calculator

Calculate a total medication dose from a weight-based rate (mg/kg) already prescribed by your doctor or pharmacist.

🧒

Pediatric Dosage Calculator

Estimate a child's medication dose as a proportion of an adult dose, using Clark's Rule (weight-based) or Young's Rule (age-based).

🦴

Corrected Calcium Calculator

Adjust a total calcium blood test result for low albumin levels using the standard Payne correction formula.

Blood Sugar Converter

Convert blood glucose readings between mg/dL (used in the US) and mmol/L (used in most other countries).

❤️

Mean Arterial Pressure (MAP) Calculator

Calculate Mean Arterial Pressure (MAP) from systolic and diastolic blood pressure readings.

Mathematics — 63 tools

🧮

Scientific Calculator

Free online scientific calculator with trigonometric, logarithmic, exponential, and root functions.

➗

Fraction Calculator

Add, subtract, multiply, or divide fractions and get the result automatically simplified.

Percentage Calculator

Calculate percentages: find X% of a number, what percent one number is of another, or the total from a percentage.

Percentage Increase/Decrease Calculator

Calculate the percentage increase or decrease between an initial value and a new value.

Percentage Error Calculator

Calculate the percentage error between a measured (experimental) value and a true (theoretical) value.

Ratio Calculator

Simplify a ratio to its lowest terms and optionally split a total amount according to that ratio.

Rounding Calculator

Round any number to a chosen number of decimal places, using round, round-down, or round-up rules.

🔬

Scientific Notation Calculator

Convert any decimal number to scientific notation, or convert a scientific notation value back to decimal.

📏

Significant Figures Calculator

Count the number of significant figures in a value, or round a number to a specific number of significant figures.

√

Square Root Calculator

Calculate the square root of any positive number instantly, and check if it's a perfect square.

∛

Cube Root Calculator

Calculate the cube root of any number — positive or negative — instantly.

Exponent & Logarithm Calculator

Calculate a number raised to a power (exponent), or find the logarithm of a number in any base.

➗

Long Division Calculator

Divide two whole numbers and see the full long division process shown step by step, including the quotient and remainder.

Decimal Calculator

Add, subtract, multiply, or divide two decimal numbers, with a clear explanation of how the decimal point is placed in the result.

🔀

Percent to Fraction Calculator

Convert any percentage into its simplest equivalent fraction, including percentages with decimal points.

🔁

Fraction to Percent Calculator

Convert any fraction into its equivalent percentage instantly.

🔁

Binary/Decimal/Hex Converter

Convert numbers between binary, octal, decimal, and hexadecimal number systems instantly.

🧩

Binary Calculator

Add, subtract, multiply, divide, or apply logical operations (AND/OR/XOR) on binary numbers.

🔡

Hex Calculator

Add, subtract, multiply, divide, or apply logical operations (AND/OR/XOR) on hexadecimal numbers.

🏛️

Roman Numerals Converter

Convert numbers to Roman numerals or convert Roman numerals back to regular numbers.

🔠

Big Number Calculator

Perform accurate arithmetic on extremely large whole numbers, beyond normal calculator precision limits.

🎲

Random Number Generator

Generate one or more random numbers within a chosen range, with or without duplicates.

📋

Mean, Median, Mode Calculator

Calculate the mean (average), median, mode, and range of any set of numbers instantly.

Standard Deviation Calculator

Calculate the standard deviation and variance of a data set, for both sample and population data.

🎰

Probability Calculator

Calculate the probability of two independent events happening together, either occurring, or not occurring.

🔀

Permutation & Combination Calculator

Calculate the number of permutations (nPr) and combinations (nCr) for any n and r.

Z-Score Calculator

Calculate the Z-score of a value relative to a mean and standard deviation, and see its approximate percentile.

🎚️

Confidence Interval Calculator

Calculate the confidence interval for a sample mean at a chosen confidence level (90%, 95%, or 99%).

👥

Sample Size Calculator

Calculate the minimum sample size needed for a survey or study, based on your desired confidence level and margin of error.

🔗

Regression Calculator

Calculate the linear regression equation (line of best fit) and correlation for a set of X, Y data points.

🧲

Correlation Calculator

Calculate Pearson's correlation coefficient (r) between two sets of paired data, and see the strength and direction of the relationship.

🧪

Chi-Square Calculator

Calculate the Chi-Square (χ²) test statistic and degrees of freedom from observed and expected frequencies.

🔔

Normal Distribution Calculator

Calculate the probability density and cumulative probability P(X ≤ x) for a normal distribution with a given mean and standard deviation.

🪙

Binomial Distribution Calculator

Calculate the probability of getting exactly k successes (or at most k) in n independent trials with a fixed success probability.

⏱️

Poisson Distribution Calculator

Calculate the probability of a given number of events occurring in a fixed interval, based on a known average rate.

Area Calculator

Calculate the area of a square, rectangle, triangle, circle, trapezoid, or parallelogram.

📦

Volume Calculator

Calculate the volume of a cube, box, sphere, cylinder, cone, or square pyramid.

🧊

Surface Area Calculator

Calculate the total surface area of a cube, box, sphere, cylinder, or cone.

📍

Distance Between Two Points Calculator

Calculate the straight-line distance between two points in 2D or 3D coordinate space.

Slope Calculator

Calculate the slope between two points, along with the line's y-intercept and angle of inclination.

🔺

Triangle Calculator

Solve a triangle's angles, area, and perimeter from three sides (SSS) or two sides and an included angle (SAS).

⭕

Circle Calculator: Area & Circumference

Calculate a circle's area, circumference, and diameter from its radius or diameter.

Pythagorean Theorem Calculator

Find a right triangle's hypotenuse from its two legs, or find a missing leg from the hypotenuse and one leg.

🧮

Quadratic Equation Solver

Solve any quadratic equation ax² + bx + c = 0 and get real or complex roots instantly.

Linear Equation Calculator

Find the equation of a straight line (slope-intercept, point-slope, and standard form) from two points.

🧩

Equation Solver

Solve a linear equation of the form ax + b = cx + d for the unknown variable x.

Inequality Calculator

Solve a linear inequality of the form ax + b (comparison) c and get the solution set for x.

Function Graphing Calculator

Plot the graph of a mathematical function y = f(x) over a custom range using an interactive canvas.

Polynomial Calculator

Add, subtract, or multiply two polynomials and get the simplified result instantly.

ℂ

Complex Number Calculator

Add, subtract, multiply, or divide two complex numbers and find the result's modulus and argument.

➡️

Vector Calculator

Add, subtract vectors, or compute their dot product, cross product, magnitude, and the angle between them.

Eigenvalue Calculator

Find the eigenvalues (and eigenvectors, when real) of a 2×2 matrix using its characteristic equation.

Derivative Calculator

Find the derivative of a polynomial function using the power rule, and evaluate it at a specific point.

∫

Integral Calculator

Find the antiderivative of a polynomial function and calculate its definite integral between two bounds.

Limit Calculator

Numerically approximate the limit of a function as x approaches a given value.

🔁

Sequence & Series Calculator

Find the nth term and the sum of the first n terms of an arithmetic or geometric sequence.

GCD Calculator

Find the greatest common divisor (GCD) of two or more integers using the Euclidean algorithm.

LCM Calculator

Find the least common multiple (LCM) of two or more integers.

🧩

Factor Calculator

Find the prime factorization and the complete list of divisors of any positive integer.

❕

Factorial Calculator

Calculate the factorial (n!) of any non-negative integer with exact big-number precision.

🔍

Prime Number Checker

Check whether a number is prime, and see its smallest prime factor if it isn't.

▦

Matrix Calculator

Add, subtract, multiply, transpose, or find the determinant and inverse of 2×2 or 3×3 matrices.

☢️

Half-Life Calculator

Solve for any missing value in the half-life decay equation: initial amount, remaining amount, half-life, or elapsed time.

Finance & Business Calculators — 28 tools

Budget Planner Calculator (50/30/20 Rule)

Plan your monthly budget using the popular 50/30/20 rule: needs, wants, and savings.

Savings Goal Calculator

Find out how many months it will take to reach your savings goal with monthly contributions and interest.

Expense Tracker Calculator

Break down your monthly expenses by category and see what percentage of your income each one takes.

Inflation Calculator

See how inflation affects the future value or purchasing power of an amount of money over time.

Salary Increase Calculator

Calculate your salary raise percentage, or find your new salary given a raise percentage.

Net Salary Calculator

Estimate your net (take-home) salary after entering your total deduction percentage (tax, insurance, etc.).

🏖️

Retirement Savings Estimator

Project how much your retirement savings could grow to by your target retirement age.

Murabaha Calculator (Cost-Plus Sale)

Calculate the total selling price and monthly installment for a Murabaha (cost-plus profit) Islamic financing agreement.

Ijara Calculator (Islamic Leasing)

Calculate the total cost of an Ijara (Islamic lease) or Ijara Muntahia Bittamleek (lease-to-own) agreement.

Diminishing Musharaka Calculator

Estimate the monthly payment for a Diminishing Musharaka (declining partnership) home or asset financing structure.

Profit Rate Calculator (Halal Alternative)

Calculate the total repayment and installment for a flat halal profit-rate financing agreement, instead of riba-based interest.

💱

Currency Converter

Convert between world currencies using live exchange rates, or enter your own rate manually.

Profit & Loss Calculator

Calculate the profit or loss and profit margin for a business or trade transaction.

🤝

Profit Sharing Calculator

Split a total profit amount between business partners based on their agreed share percentages.

🏷️

Margin & Markup Calculator

Calculate profit margin and markup percentage from cost and selling price, or find the required selling price.

Break-Even Point Calculator

Find out how many units you need to sell to cover your fixed and variable costs (break-even point).

🚀

Startup Cost Calculator

Estimate the total starting cost for a new business, including a recommended contingency buffer.

Cash Flow Calculator

Calculate your net cash flow for a period based on total cash inflows and outflows.

📦

Inventory Turnover Calculator

Calculate how quickly your inventory is sold and replaced over a given period.

⏱️

Payback Period Calculator

Calculate how long it will take for an investment to pay for itself from its net cash inflows.

🏷️

Discount & Sale Price Calculator

Calculate the sale price after a discount, or find the discount percentage between two prices.

🧮

VAT / Sales Tax Calculator

Calculate VAT or sales tax, whether your amount already includes tax or excludes it.

💻

Freelance Hourly Rate Calculator

Calculate the hourly rate you need to charge as a freelancer to hit your income goal.

Trade Investment Return Calculator

Calculate the return on investment (ROI) and annualized return for a trade or business investment.

🌍

GDP Calculator (Expenditure Approach)

Calculate Gross Domestic Product (GDP) using the expenditure approach: consumption, investment, government spending, and net exports.

Salary Converter

Convert your salary between hourly, daily, weekly, monthly, and annual figures based on your work schedule.

🏡

Property Tax Calculator

Estimate your annual and monthly property tax based on your home's value, assessment ratio, and local tax rate.

🤝

Commission Calculator

Calculate sales commission earnings using a flat rate, or a two-tier structure with a higher rate above a sales threshold.

Date & Time Calculators — 11 tools

🎂

Age Calculator (Gregorian & Hijri)

Calculate your exact age in years, months, and days from your date of birth — with an automatic Hijri (Islamic) calendar age conversion.

👥

Age Difference Calculator

Find the exact age gap between two people in years, months, and days, and see who is older.

🎉

Birthday Countdown Calculator

Count down the days remaining until your next birthday, and find out what age you'll be turning.

📆

Date Difference Calculator

Calculate the exact number of days, weeks, months, and years between any two dates.

💼

Business Days Calculator

Count the actual working (business) days between two dates, excluding weekends and any holidays you list.

➕

Add/Subtract Days Calculator

Add or subtract a number of days from any date to instantly find the resulting date and its day of the week.

📋

Days Between Multiple Dates Calculator

Enter several dates at once and see the days between each consecutive pair, plus the total span from earliest to latest.

📅

Day of the Week Calculator

Find out instantly which day of the week any date falls on — past, present, or future.

⏱️

Time Duration Calculator

Find the exact duration in hours and minutes between a start time and an end time, including times that cross midnight.

🕘

Work Hours & Attendance Calculator

Calculate total hours worked from clock-in and clock-out times, after subtracting unpaid break time — with an optional pay estimate.

🌐

Time Zone Converter

Convert a date and time from one time zone to another, accounting for daylight saving time automatically.

Construction & Home Improvement Calculators — 18 tools

🪣

Concrete Calculator

Calculate how much concrete (in cubic meters and tons) you need for a slab, footing, or foundation.

⚗️

Cement Calculator

Convert a concrete volume into the exact number of cement bags, plus sand and aggregate quantities, for a chosen mix ratio.

🧱

Brick Calculator

Calculate the number of bricks needed for a wall based on its dimensions, brick size, and mortar joint thickness.

🏖️

Gravel & Sand Calculator

Calculate the volume and weight of gravel, sand, or crushed stone needed to cover an area at a given depth.

🔲

Tile Calculator

Calculate the number of tiles and boxes needed to cover a floor or wall, including a wastage allowance for cuts.

🪵

Flooring Calculator

Calculate how much flooring material you need — laminate/vinyl planks or carpet rolls — for any room.

Drywall Calculator

Calculate how many gypsum/drywall sheets you need to cover a wall or ceiling area, plus an estimated screw count.

🏠

Roofing Calculator

Calculate the actual roof surface area (adjusted for pitch) and how many roofing material units you need.

🗺️

Land Area Calculator

Calculate the area of a plot of land in square meters, and convert it instantly to square feet, acres, and hectares.

🪜

Stair Calculator

Calculate the number of steps, riser height, tread depth, and stringer length for a comfortable, code-friendly staircase.

Construction Cost Calculator

Get a rough estimate of total construction cost based on built-up area, number of floors, and cost per square meter.

🚧

Fence Calculator

Calculate the number of fence posts and total rail length needed for a fence of a given length.

🌱

Mulch & Soil Calculator

Calculate the volume, bags, and weight of mulch, topsoil, or compost needed to cover a garden bed at a given depth.

🌡️

BTU Calculator

Estimate the air conditioner or heater capacity (in BTU) needed for a room, based on its size, sun exposure, and use.

🎨

Paint Calculator

Calculate how many liters of paint you need for a wall or room based on area, number of coats, and coverage rate.

🖌️

Paint Coverage Calculator

Find out how many paint cans of a given size you need to buy to cover a specific area, based on the coverage rate per liter.

🛣️

Asphalt Calculator

Calculate how many tons of asphalt you need for a driveway, road, or parking lot based on area and thickness.

🔩

Rebar Calculator

Calculate the number and total weight of reinforcing steel bars (rebar) needed for a concrete slab based on its dimensions and bar spacing.

Engineering & Science Calculators — 35 tools

⚡

Ohm's Law Calculator

Calculate voltage, current, or resistance instantly using Ohm's Law (V = I × R) — just enter any two values.

🔩

Resistance Calculator

Calculate the total resistance of up to five resistors connected in series or parallel.

🔌

Voltage Drop Calculator

Estimate the voltage drop across a wire run based on its length, cross-sectional area, material, and current load.

💡

Watt Calculator

Calculate electrical power in watts from voltage and current, or find the missing voltage or current value.

🔋

Capacitance Calculator

Calculate capacitance from stored charge and voltage, or combine multiple capacitors in series or parallel.

🌀

Inductance Calculator

Calculate inductive reactance, inductance, or frequency using the inductive reactance formula (XL = 2πfL).

🕐

RC Circuit Calculator

Calculate the time constant of a resistor-capacitor (RC) circuit, and the voltage during charging or discharging at any given time.

Power Factor Calculator

Calculate the power factor of an AC circuit from real and apparent power, from real and reactive power, or from the phase angle.

💎

LED Resistor Calculator

Find the correct current-limiting resistor value (and its power rating) for one or more LEDs in series on a given supply voltage.

🔋

Battery Life Calculator

Estimate how long a battery will last based on its capacity and your device's current or power draw, including a real-world efficiency factor.

🧲

Force Calculator

Calculate force, mass, or acceleration using Newton's second law of motion (F = m × a).

🔘

Pressure Calculator

Calculate pressure, force, or area using the fundamental pressure formula (P = F ÷ A), with results shown in Pascals, bar, atm, and psi.

🛠️

Work Calculator

Calculate mechanical work done by a force using W = F × d × cos(θ), where θ is the angle between the force and the direction of motion.

🚀

Power Calculator (Mechanical)

Calculate mechanical power from work and time, or from force and velocity — the rate at which work is done or energy is transferred.

Momentum Calculator

Calculate linear momentum, mass, or velocity using the formula p = m × v.

💨

Kinetic Energy Calculator

Calculate the kinetic energy, mass, or velocity of a moving object using KE = ½ × m × v².

⛰️

Potential Energy Calculator

Calculate gravitational potential energy, mass, or height using PE = m × g × h.

Projectile Motion Calculator

Calculate the time of flight, maximum height, and horizontal range of a projectile launched at an angle, using standard kinematics equations.

🔧

Torque Calculator

Calculate the torque (rotational force) produced by a force applied at a distance from a pivot point, using τ = F × r × sin(θ).

⚗️

Mole Calculator

Convert between mass, moles, and molar mass, and find the number of particles using Avogadro's number.

Dilution Calculator

Calculate the final concentration or volume needed when diluting a solution, using the dilution formula C₁V₁ = C₂V₂.

🧪

pH Calculator

Calculate pH from hydrogen ion concentration, or hydrogen ion concentration from pH — including the corresponding pOH and hydroxide ion concentration.

🎈

Ideal & General Gas Law Calculator

Solve for pressure, volume, moles, or temperature using the ideal gas law PV = nRT.

Reaction Stoichiometry Calculator

Calculate the moles and mass of a product or reactant in a balanced chemical reaction, using the mole ratio between two substances.

🔄

Unit Converter

Convert instantly between common units of length, weight/mass, volume, and temperature.

🏎️

Speed Calculator

Calculate speed, distance, or time using the relationship Speed = Distance ÷ Time — solve for any one of the three.

🧱

Density Calculator

Calculate density, mass, or volume using the relationship Density = Mass ÷ Volume — solve for any one of the three.

🏋️

Mass & Weight Calculator

Calculate an object's weight (gravitational force) from its mass, or its mass from a known weight, on Earth or other bodies in the solar system.

🧫

Molarity Calculator

Calculate the molarity, moles, or volume of a solution using the relationship Molarity = Moles of solute ÷ Volume of solution (in liters).

Molecular Weight Calculator

Calculate the molecular (molar) weight of a chemical compound automatically from its formula, such as H2O, NaCl, or Ca(OH)2.

⚡

Generator Size Calculator

Estimate the generator capacity (watts) you need based on your total running load and the highest starting surge among your appliances.

🎨

Resistor Color Code Calculator

Decode a 4-band resistor's color code into its resistance value and tolerance percentage.

🌊

Reynolds Number Calculator

Calculate the Reynolds number for fluid flow in a pipe to determine whether the flow is laminar, transitional, or turbulent.

Bernoulli Equation Calculator

Solve Bernoulli's equation for fluid pressure at a second point in a flow system, given pressure, velocity, and height at two points.

🚰

Pipe Volume Calculator

Calculate the internal volume of a cylindrical pipe or tube in liters and cubic meters, based on its inside diameter and length.

Technology & Internet Tools — 13 tools

🌐

Subnet Calculator

Calculate network address, broadcast address, usable host range, subnet mask, and number of hosts from any IPv4 address and CIDR prefix.

🔑

Password Generator

Generate strong, random, hard-to-guess passwords instantly using your browser's secure random number generator — fully customizable length and character types.

📶

Bandwidth Calculator

Estimate how long a file will take to download (or upload) based on its size and your internet connection speed.

🔤

Base64 Encoder/Decoder

Encode any text into Base64 format, or decode a Base64 string back into readable text — instantly, right in your browser.

🔗

URL Encoder/Decoder

Encode text or a full URL into a safe percent-encoded format, or decode a percent-encoded URL back into readable text.

🎨

Color Converter – HEX/RGB

Convert colors instantly between HEX code and RGB values, with a live color preview swatch.

JSON Formatter

Beautify (pretty-print) or minify any JSON text instantly, with clear error messages if the JSON is invalid.

🆔

UUID Generator

Generate one or many random Version 4 UUIDs (universally unique identifiers) instantly, using your browser's secure random generator.

🔒

Hash Generator (MD5/SHA)

Generate MD5, SHA-1, SHA-256, and SHA-512 hash digests of any text instantly, all calculated locally in your browser.

🖥️

Screen Size & Aspect Ratio Calculator

Calculate a screen's aspect ratio (like 16:9) from its resolution, and optionally its physical diagonal size in inches and centimeters if you know its pixel density (PPI).

💾

File Size Calculator

Estimate the uncompressed file size of an image, audio clip, or video based on its technical parameters.

🗄️

Data Storage Converter

Convert between bits, bytes, kilobytes, megabytes, gigabytes, and terabytes, using either decimal (1000-based) or binary (1024-based) units.

🔳

QR Code Generator

Generate a scannable QR code from any text, URL, or message — created entirely in your browser using a hand-built QR encoding engine, with no external service involved.

Education Calculators — 10 tools

🎓

GPA Calculator

Calculate your semester GPA (Grade Point Average) on a 4.0 scale from your course grades and credit hours.

📚

CGPA Calculator

Calculate your CGPA (Cumulative Grade Point Average) across multiple semesters or years of study, combining each semester's GPA and credit hours.

📝

Grade Percentage Calculator

Calculate the percentage score of your grade from the marks you obtained out of the total possible marks, with an equivalent letter grade.

Final Grade Calculator

Find out what score you need on your final exam to reach your desired overall course grade, based on your current grade and the final exam's weight.

✅

Required Exam Score Calculator

Calculate the minimum score you need on a remaining exam to reach a passing grade, based on the scores and weights of everything else in the course.

Weighted Grade Calculator

Calculate your overall course grade from multiple categories (like homework, quizzes, midterms, and final exam) each with its own percentage weight.

🏛️

University Admission Estimator

Get a general, informational estimate of which broad field of university study your high school percentage may realistically qualify you for, based on commonly used percentage bands.

Word & Character Counter Calculator

Count the number of words, characters (with and without spaces), sentences, and paragraphs in any text, plus an estimated reading time.

⏳

Study Time Calculator

Work out how many study hours you need before an exam, how many days you have left, and how many hours per day that requires to cover every topic on time.

🍅

Study Timer / Pomodoro Calculator

Plan how many focused Pomodoro study sessions fit into the time you have, and run a live work/break countdown timer for your study session.

Automotive & Transportation Calculators — 10 tools

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Fuel Consumption Calculator

Calculate your car's fuel consumption in liters per 100 km (and the equivalent miles per gallon) from the distance traveled and the fuel used.

Trip Fuel Cost Calculator

Estimate the total fuel cost of a trip based on the distance, your car's fuel consumption rate, and the local price of fuel.

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Distance Between Cities Calculator

Calculate the straight-line (great-circle) distance between two major world cities in kilometers and miles.

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Horsepower Calculator

Calculate an engine's horsepower from its torque and RPM (revolutions per minute), and see the equivalent power in kilowatts.

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Tire Size Calculator

Decode a tire size code (like 205/55R16) into its actual sidewall height, overall diameter, and circumference, and compare it against a second tire size.

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Stopping Distance Calculator

Estimate a vehicle's total stopping distance — combining reaction distance and braking distance — based on speed, driver reaction time, and road surface condition.

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Gear Ratio Calculator

Calculate the gear ratio between a drive gear and a driven gear from their number of teeth, and find the resulting output speed and torque multiplier.

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Engine RPM Calculator

Calculate a car's engine RPM at a given road speed, based on the tire diameter, transmission gear ratio, and final drive (differential) ratio.

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EV Charging Time Calculator

Estimate how long it will take to charge an electric vehicle's battery from a starting charge percentage to a target percentage, based on charger power and charging efficiency.

Car Depreciation Calculator

Estimate how much your car's value will decline over the next few years using a fixed annual depreciation rate, and see the estimated resale value year by year.

Everyday & Personal Tools — 18 tools

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Tip Calculator

Calculate the tip amount and total bill for a restaurant check, and split it evenly between any number of people.

Bill Split Calculator

Split a shared bill fairly between friends, with the option to give some people a different number of shares than others.

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Cooking Measurement Converter

Convert common cooking and baking measurements between cups, tablespoons, teaspoons, milliliters, fluid ounces, and liters.

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Pet Age Calculator

Estimate your dog or cat's equivalent human age using modern veterinary age-conversion guidance that accounts for their actual age and size, not just a simple ×7 multiplier.

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Shoe Size Converter

Convert shoe sizes between US, UK, EU, and foot length in centimeters, for men's and women's sizing.

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Bra Size Calculator

Estimate your bra band size and cup size from your band measurement (underbust) and bust measurement, using the standard sister-size method.

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Heat Index Calculator

Calculate the heat index ("feels like" temperature) from air temperature and relative humidity, using the official NOAA formula.

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Wind Chill Calculator

Calculate the wind chill ("feels like" temperature in cold, windy conditions) from air temperature and wind speed, using the official NWS formula.

Dew Point Calculator

Calculate the dew point temperature from air temperature and relative humidity, using the Magnus-Tetens approximation formula.

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Cooking Time Calculator

Estimate roasting time for chicken, turkey, beef, pork, or ham based on weight and a standard oven temperature.

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Sleep Debt Calculator

Estimate your accumulated sleep debt by comparing your actual average sleep to your target amount over a number of nights.

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Golf Handicap Calculator

Estimate a simplified golf handicap index from one or more rounds using your score, course rating, and slope rating.

Darts Calculator

Find a valid double-out checkout combination for any remaining score from 2 to 170 in a standard 501 or 301 darts game.

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Sunrise & Sunset Calculator

Estimate sunrise and sunset times for any date and location using latitude, longitude, and your UTC time zone offset.

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Moon Phase Calculator

Find the moon's phase and approximate illumination percentage for any date using the synodic (lunar) month cycle.

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Horse Gestation Calculator

Estimate a mare's expected foaling date range based on the breeding or covering date.

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Dog Pregnancy Calculator

Estimate a dog's expected whelping date range based on the mating date.

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Cat Pregnancy Calculator

Estimate a cat's expected queening (birth) date range based on the mating date.

Islamic Tools & Calculators — 41 tools

Zakat Calculator

Calculate your total Zakat (2.5%) on cash, savings, gold, silver, trade assets, and receivables, minus due debts, compared against the gold or silver Nisab threshold.