Hiking Time Calculator
Estimate how long a hike will take using Naismith's rule, based on distance and total ascent.
This assumes a fit walker with a light pack on a clear trail. Add roughly 25% for a heavy pack, rough or muddy terrain, or hiking with kids. Steep descents cost time too, they aren't free just because you're going downhill. Leave a margin for breaks and daylight, especially if you're turning around at a fixed time.
How it works
This tool uses Naismith's rule, the standard back-of-envelope formula hikers have used for over a century to estimate trail time. It gives you 1 hour for every 3 miles of flat distance, plus 1 extra hour for every 2000 ft of total ascent. The two numbers add together, so a hike with a lot of climbing takes noticeably longer than the flat distance alone suggests, even if the mileage looks modest on a map.
Worked example: a 6 mile hike with 1000 ft of total climbing. The flat-distance portion is 6 divided by 3, times 60 minutes, which is 120 minutes. The climbing portion is 1000 divided by 2000, times 60 minutes, which is 30 minutes. Add them together and you get 150 minutes, or 2 hours 30 minutes. That's before any stops for water, snacks, photos, or a break at the summit, so treat it as moving time, not door-to-door time.
FAQ
Does this account for a heavy pack or rough terrain?
No, the base formula assumes a fit walker with a light day pack on a reasonably clear trail. If you're carrying overnight gear, crossing loose scree, or hiking with kids, add roughly 25% to the estimate. On a bad trail day (mud, snow, deadfall) add even more.
Why does descent count the same as flat ground here?
The formula folds descent into the flat-distance calculation, which works fine on moderate grades. On genuinely steep, technical descents, especially with loose footing, going down can take just as long as going up, so budget extra time rather than assuming the way back is automatically faster.
How much of a time margin should I build in?
Enough that you're never racing the sunset. A common rule is to double the estimate for your turnaround planning on an unfamiliar trail: if the round trip is estimated at 5 hours, plan to be back at the trailhead with 2 to 3 hours of daylight to spare.
Is this accurate for very short or very long hikes?
It's most reliable for day hikes in the few-mile-to-10-mile range. On very long backpacking days, fatigue slows you down more than the formula predicts, so pad the estimate further for each additional hour on your feet.
For more on planning a realistic pace and knowing your limits, see how to pace yourself and build hiking endurance, how to read a trail's difficulty, distance, and elevation, and how to know when to turn back on a hike.