How this calculator works
Naismith rule adds two times: the horizontal distance at a walking pace and the climbing time at one hour per 600 m of ascent. This page uses 5 km/h on paths and tracks and 4 km/h on rough ground. It then adds a descent allowance, about 3 minutes per 100 m on gentle slopes and 6 minutes per 100 m on steep ones, because descending also takes time and care. Breaks are added last. The rule is a planning estimate from the Scottish hills and assumes a steady, unhurried pace.
Formula
Flat time (hours) = distance in km / speed in km/h. Climbing time (hours) = ascent in metres / 600. Descent time (hours) = descent in metres x rate, where the rate is 0.0005 for gentle and 0.001 for steep. Total = flat + climbing + descent + breaks.
Worked example
A 10 km walk on paths with 500 m of ascent and 500 m of descent, gentle slopes and a 30 minute break: flat time is 10 / 5 = 2 hours, climbing is 500 / 600 = 0.833 hours, and descent is 500 x 0.0005 = 0.25 hours. The time on the move is 3.08 hours, and with the break the day is 3.58 hours, or about 3 hours 35 minutes.
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Frequently asked questions
What is Naismith rule?
A navigation and planning rule from 1892: allow one hour for every 5 km of distance and one hour for every 600 m of ascent. It is a starting point, not a pace guarantee.
Why add time for descent?
Naismith rule ignores downhill, but steep descents are slow and tiring, especially with loose rock or wet ground. The small allowance here brings the estimate closer to a real hill day.
Does fitness change the estimate?
Yes. The rule is a moderate group pace. A fit walker may move faster, while a large group, a heavy pack, bad weather or poor visibility can add hours.
Should I add time for navigation?
If the route needs map, compass or GPS work, add it to the breaks or keep a margin. The base rule assumes you know the way and keep moving.