Hiking Time Calculator (Naismith’s Rule)
Estimates a day in the hills from the distance and the climbing, the way hill walkers usually plan a route.
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The formula
Naismith: time = distance ÷ 5 km/h + ascent ÷ 600 m/h Tobler: speed = 6 × e^(−3.5 × |slope + 0.05|) km/h
Naismith’s rule dates from 1892 and allows an hour per 5 km, plus an hour per 600 m climbed. Tobler’s hiking function gives a speed for any slope, and is fastest on a slight downhill.
What to watch out for
Compare your own past walks with the result, then adjust.
Frequently Asked Questions
What is Naismith’s rule?
Allow one hour for every 5 km, plus one hour for every 600 m of ascent. A 12 km walk with 700 m of climbing comes to 3 h 34 min, before rests.
What does Tobler’s function say on the flat?
5.04 km/h. Its top speed, 6.0 km/h, is on a slight downhill of 5%.
Why does Naismith’s rule ignore descent?
It is a simple rule: going down is treated as taking about as long as the flat. Steep descents are slower than that, which is one place the two methods differ.