Estimate how long a hike will take based on distance, elevation gain, and pace using Naismith's Rule.
Fill in the fields on the left with your information, then press Calculate to see your result instantly. No sign-up required, and no data is sent anywhere — everything is calculated right in your browser.
Naismith's Rule, first published in 1892 by Scottish mountaineer William Naismith, is a widely used method for estimating hiking and mountaineering time. It combines a base walking speed with an additional time allowance for climbing: roughly one extra hour for every 600 meters of elevation gained. This calculator applies the rule using your chosen distance, total elevation gain, and walking pace. It gives a reasonable baseline for trip planning, though it does not account for rest stops, difficult terrain, or fitness level, so experienced hikers often adjust the result up or down based on personal experience. Scottish mathematician William Naismith proposed his rule in 1892: one hour per 5 kilometers of horizontal distance, plus 30 minutes per 300 meters of ascent — and it remains the basis of most hiking-time calculators well over a century later. The Tranter correction, a later refinement, better accounts for gradually slowing pace as terrain steepens, though neither adjusts for trail surface, pack weight, or individual fitness, all of which can meaningfully change real-world time.
Estimating how long a hike will take sounds simple, but distance alone is a poor predictor — a flat 5-mile trail and a 5-mile trail with 3,000 feet of elevation gain take dramatically different amounts of time and effort, yet a distance-only estimate would treat them identically. This calculator is built on Naismith's Rule, developed by Scottish mountaineer William Naismith in 1892, which remains the most widely used baseline formula in hiking and mountaineering for exactly this reason: it accounts for both horizontal distance and vertical elevation gain.
The original rule allows one hour for every 5 kilometers (about 3 miles) of horizontal distance, plus an additional 30 minutes for every 300 meters (about 1,000 feet) of ascent. Over more than a century of use, several modifications have been proposed to improve its accuracy for different conditions — Tranter's corrections adjust for fitness level and pack weight, while other variants account for rough or technical terrain, which can slow hikers considerably more than elevation gain alone would suggest.
Naismith's Rule was originally calibrated for a fit, unencumbered hiker moving at a brisk, sustainable pace on reasonably clear trails, so real-world hiking times for less experienced hikers, those carrying heavy packs, or groups moving at the pace of their slowest member typically run noticeably longer than the raw formula predicts — many experienced hikers add a buffer of 25-50% to the base Naismith estimate for exactly this reason, especially for longer or more technical routes.
Beyond simple curiosity, an accurate time estimate has real safety implications: it's the foundation for deciding what time to start a hike to finish before dark, how much water and food to carry, and whether a route is realistic for a given group's fitness level and daylight window — treating the calculator's output as a rough guide to plan around, rather than a guaranteed finish time, is the safest way to use it.
No, the estimate is pure walking and climbing time. Add extra time for snack, photo, and rest stops on longer hikes.
No — it estimates based on distance and elevation gain only, so rough terrain, heavy packs, heat, or poor weather can meaningfully extend actual hiking time beyond the calculated estimate.
This calculator focuses on ascent time, which dominates most hiking pace calculations. Steep descents can also slow you down and may need extra time.
It's a general guideline based on an average fit hiker. Beginners, children, or hikers carrying heavy packs may need significantly more time.