Calculation methods
- Naismith's rule (Scotland, 1892): 5 km/h, plus 1 hour per 600 m of ascent.
- DIN 33466 (German standard used by alpine clubs): 4 km/h on the flat, 300 m of ascent and 500 m of descent per hour; keep the larger of the two times and add half the smaller.
- Effort-kilometres: distance + ascent / 100, walked at about 4 effort-km per hour.
These are moving times, without breaks: add them (the tool does it with the setting you choose). Real pace depends on terrain, pack weight, weather and the group.
How do I import a track?
Export the route as GPX from your app (Komoot, AllTrails, OS Maps, Strava, Garmin…) and open it here. The file is not uploaded: it is read in your browser.
What about safety?
Keep a margin before dark, check the mountain forecast and tell someone your route.
How to use it
- Describe the route: distance, total ascent and descent, or import a GPX track (the elevation profile and climbs are then computed from its points).
- Pick a method (DIN 33466, Naismith or effort-kilometres) and your pace: from “fast” to “with children or beginners”, it scales the estimate.
- Set breaks as a percentage of walking time (15% by default) and your start time.
- Read the timings and the latest start time before sunset, computed for the place and date. Print the sheet and keep it in your pack.
Example: a 12 km loop with 800 m up and 800 m down
- DIN 33466: 3 h for the distance (12 km at 4 km/h), 4 h 16 for the climbs (800 m up at 300 m/h + 800 m down at 500 m/h). Keep the larger (4 h 16) and add half the smaller (1 h 30): about 5 h 46 of walking.
- Naismith: 12 km at 5 km/h = 2 h 24, plus 1 h 20 for 800 m of ascent: 3 h 44. This rule, designed for fit walkers, ignores descent.
- Effort-kilometres: 12 + 800 / 100 = 20 effort-km, i.e. 5 h at 4 effort-km per hour.
- With 15% breaks, the DIN estimate becomes about 6 h 38: leaving at 9:00 means arriving around 15:40.
The methods disagree because they target different walkers. For a first outing with a group, use the most cautious one.
Common mistakes
- Forgetting the descent: on steep or rocky paths, dropping 1,000 m often takes over 2 hours and is hard on the knees.
- Trusting the ascent of a noisy track: phone recordings often overstate climbing by 10–30%. Check against a topographic map.
- Starting too late: in autumn darkness comes early; keep at least an hour in hand.
Planning your day
Use the Sun and moon tool to know when civil twilight ends, and print a day-hike checklist so you forget nothing (water, head torch, emergency blanket, first-aid kit).
Guide written and checked by Erwan Hautot · updated 5 November 2026.