Calculate your daily calorie needs based on your goal: lose, maintain, or gain weight.
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Your daily calorie needs depend on your basal metabolic rate (the energy your body uses at rest) and your activity level, then adjusted based on your goal. This calculator uses the Mifflin-St Jeor equation — widely regarded by dietitians as the most accurate standard formula — to estimate your maintenance calories, then applies a moderate, sustainable adjustment for weight loss or gain rather than extreme deficits or surpluses. Total Daily Energy Expenditure (TDEE) is calculated by multiplying BMR by an activity multiplier reflecting daily movement — from about 1.2 for sedentary lifestyles to 1.9 or higher for very physically demanding routines. Once TDEE is estimated, setting a calorie target is simple arithmetic: matching it maintains weight, a deficit of roughly 300-750 calories daily supports gradual healthy loss, and a moderate surplus supports muscle gain. Because this number depends on an estimated BMR multiplied by a subjectively-chosen activity level, small inaccuracies in either input compound into a noticeably different final target — which is exactly why real-world weight tracking over several weeks is the most reliable way to confirm whether the calculated target actually matches your body's true energy balance.
Total Daily Energy Expenditure (TDEE) — often the number people actually mean when they ask "how many calories should I eat" — is calculated by taking Basal Metabolic Rate (BMR, the energy needed at complete rest) and multiplying it by an activity factor that accounts for everything from walking around the house to structured exercise. This calculator uses the widely-referenced Harris-Benedict activity multiplier scale, ranging from roughly 1.2 for a sedentary lifestyle with little to no exercise, up to 1.9 for extremely active individuals with physical jobs plus intense daily training.
Choosing the right activity level is the single biggest source of error in any calorie calculator, more than any imprecision in the BMR formula itself, because people consistently overestimate how active they really are — a category most people assume applies to them ("moderately active") often assumes structured exercise 3-5 days a week, which doesn't describe someone who works at a desk and occasionally walks the dog. Being honest, and if anything erring toward the more conservative activity category, generally produces a more useful starting estimate.
Once TDEE is established, a calorie target for weight loss, maintenance, or gain is set by creating a deficit or surplus relative to that number — a deficit of roughly 500 calories per day is a commonly cited (though approximate) rate for losing about one pound of body weight per week, since a pound of fat contains roughly 3,500 calories, though real-world weight change involves considerably more variability than this simple math suggests, due to water retention, hormonal factors, and the body's own metabolic adaptation to sustained deficits.
Because both BMR formulas and activity multipliers are population averages rather than a measurement of any specific individual, the number this calculator returns is best used as a starting point to be adjusted based on real, tracked results over two to three weeks — if actual weight change doesn't match the math, the calorie target should be adjusted rather than assuming the tracking itself was wrong.
For most healthy adults, a moderate deficit of about 500 kcal/day supports gradual, sustainable weight loss of roughly 0.5 kg per week.
Track your actual weight for two to three weeks while following the target — if the change doesn't match expectations, adjust the calories up or down slightly rather than trusting the estimate blindly.
Yes — recalculate every few weeks since your calorie needs shift as your weight and activity level change.