The formula
The calculator uses the method of the German standard DIN 33466, which is also behind many trail signs in the Alps. An average hiker walks:
- 4 km per hour on the flat,
- 300 m of ascent per hour,
- 500 m of descent per hour.
The time for the distance and the time for the height difference are calculated separately; the total is the bigger of the two plus half of the smaller one. Example: 12 km is 3 h, 1100 m up and down is 3.7 h + 2.2 h = 5.9 h, so the walking time is 5.9 h + 3 h / 2 ≈ 7.4 h.
The formula assumes good paths. On scree, snow, via ferratas or unmarked terrain you are much slower – easily 1.5 to 2 times. Times on trail signs are meant for an average hiker and usually do not include breaks.
Before you go: check the weather, the sunset time and how cold it gets at the top with the Mountain Weather tool. My tours are in the Adventures Logbook.
Mountains are not a calculator. Weather, conditions, fitness and experience change everything. Use these numbers for planning, and turn back in time.