Key Takeaways
- Naismith's rule: one hour for every 5 km, plus one hour for every 600 m of ascent[1]. A 12 km walk with 800 m of climbing comes to 3 h 44 min of walking.
- Published rules give different answers for the same route. For that walk they run from 3 h 14 min to 4 h 47 min.
- Naismith's rule counts walking time only. Breaks, lunch and navigation come on top, and the Plan the day tab adds them.
- Apps and signposts overestimated recorded times on 25 Italian loop trails[5]. Check any estimate against your own past walks.
How the Calculator Works
The Estimate tab takes your distance, ascent and descent and shows moving time under each rule below. The Plan the day tab takes one of them, adds your breaks, and gives a finish time. Your entries stay in your browser and nothing is sent anywhere.
| Method | How it is worked out | Source |
|---|---|---|
| Naismith's rule | Distance ÷ 5 km/h + ascent ÷ 600 m/h | Naismith, 1892[1] |
| Langmuir's descent correction | Naismith, then 10 min off per 300 m of descent on gentle slopes, and 10 min added on steep ones | Langmuir, via Wikipedia[3] |
| Tobler's hiking function | Speed = 6 × e^(−3.5 × |slope + 0.05|) km/h, applied to the climbing and descending parts | Tobler, via Wikipedia[4] |
| Group pace | Distance ÷ 4 km/h + ascent ÷ 450 m/h | Langmuir, via Wikipedia[3] |
| Your own pace | (Distance + 8 or 10 × ascent) ÷ your flat speed | Scarf, 2007[2] |
What each method works out, and where it comes from. Source numbers match the sources list.
The 1892 journal, Langmuir's handbook and Tobler's original report are quoted here from Wikipedia's summaries, and the table says so.
Naismith's Rule: How to Calculate Hiking Time
William Naismith, a Scottish mountaineer, wrote the rule down in 1892: an hour for every three miles on the map, plus an hour for every 2,000 feet of ascent[1]. The metric form used here is 5 km per hour and 600 m of ascent per hour.
Worked example: 12 km with 800 m of ascent
12 ÷ 5 = 2.4 hours for the distance. 800 ÷ 600 = 1.33 hours for the climb. Together that is 3 h 44 min of walking, before any breaks.
The rule assumes a walker of reasonable fitness, on typical ground, in normal conditions. It ignores rests and navigation, it is usually treated as a minimum time, and it cannot be used for scrambling routes[1].
The rule also says something about climbing. Scarf worked out that it counts 1 m of ascent as 7.92 m of flat travel, and fell-running records supported 1:8 for men and 1:10 for women[2].
That lets you use your own speed. At 5 km/h, a 20 km route with 1,600 m of climbing is 20 + 8 × 1.6 = 32.8 km of flat-equivalent walking, or 6 h 34 min.
Those ratios come from fell running. Scarf's paper also reports 1:3.3 from treadmill running experiments, 1:4.4 from a mountain road relay and 1:8.2 for cycling, so the equivalence depends on the activity[2].
For a check on the units, the original rule gives 2 hours for 3 miles and 2,000 ft. The metric form gives 1 h 59 min for the same route.
Naismith, Langmuir and Tobler Compared
Langmuir added a correction for descents. On gentle slopes of 5 to 12 degrees you subtract 10 minutes per 300 m of descent, and on steeper ones you add 10 minutes per 300 m[3]. The accuracy of the gentle-descent correction is disputed[1].
For groups, Langmuir gave a slower pace of 4 km/h plus an hour per 450 m of ascent[3].
Tobler's function sets walking speed from the slope, using data from the Swiss cartographer Eduard Imhof. It gives 5.04 km/h on the flat and a peak of 6 km/h on a 5% downhill. Climbing, it gives 3.55 km/h at 10% and 2.50 km/h at 20%[4].
Tobler also gave a factor of 3/5 for walking off paths, which this tool does not apply[4].
Worked example: a 12 km loop with 800 m up and 800 m down
Naismith gives 3 h 44 min. Langmuir's correction takes 27 minutes off, to 3 h 17 min. Tobler gives 3 h 14 min and the group pace gives 4 h 47 min.
At 4 km/h with the 1:8 climb allowance, your own pace gives 4 h 36 min.
Tobler and Langmuir both need a slope, and your inputs only give totals. This tool splits the distance between climbing and descending in proportion to your ascent and descent, then treats each part as one steady gradient. That split is an assumption of this tool, not a published method, so read those two rows as a guide.
A 2023 review of hiking-time formulas cites all three of these authors[6]. No source ranks them for accuracy, so the tool shows them side by side instead of picking one.
How Long Does a Hike Take?
| Distance | Flat | 300 m up | 600 m up | 1,000 m up |
|---|---|---|---|---|
| 5 km | 1 h | 1 h 30 min | 2 h | 2 h 40 min |
| 10 km | 2 h | 2 h 30 min | 3 h | 3 h 40 min |
| 15 km | 3 h | 3 h 30 min | 4 h | 4 h 40 min |
| 20 km | 4 h | 4 h 30 min | 5 h | 5 h 40 min |
Moving time by Naismith's rule (5 km/h plus 600 m of ascent per hour), with no breaks. A rule of thumb, not measured times.
In miles, 10 flat miles is 3 h 13 min at Naismith's 5 km/h. The Italian Alpine Club's signposts, as described in one study, assume 3.5 to 4 km/h on flat sections and 350 m of ascent or 500 m of descent per hour[5].
There is no published average hiking speed for the general public. If you have recorded walks, enter your own flat speed on the Estimate tab, since that is a better base than any average.
How Accurate Are Hiking Time Estimates?
Vecchiato and colleagues compared GPS times uploaded by at least 20 users per trail on 25 Italian loop trails with several published estimates. Estimated times were longer than the real ones by 48.9 minutes for Komoot, 69.1 for Outdooractive and 29.6 for the signposts, on average[5].
The spread was wide, about 57 to 60 minutes either side of each average. The study did not test Naismith's rule, Tobler's function or Langmuir's corrections, so it says nothing about how accurate they are.
The authors' own algorithm, MOVE, uses individual and trail data and showed no significant average difference (0.3 minutes, with a spread of about 66)[5]. This tool does not use it.
Planning the Day: Breaks, Finish Time and Sunset
The rules give walking time only. The Plan the day tab adds minutes of break per hour of walking plus any fixed stops, and works out your finish time.
Worked example: 15 km with 750 m up and down, a 09:00 start
Naismith gives 4 h 15 min of walking. Add 10 minutes of break per hour and a 30 minute lunch and the total is 5 h 28 min, so you finish at 14:28. With a sunset time of 16:45, that is 2 h 18 min before sunset.
You type the sunset time in, because the tool does not look it up. Check it for your date and place. For pacing, see the Zone 2 heart rate calculator and the run-walk pace calculator.
Limits of These Estimates
- Pack weight, weather, snow, altitude, age, fitness, rough ground and navigation are not adjusted for, because no validated factor exists for them. Allow extra time.
- These rules describe walking, not scrambling. The tool shows a warning when the climbing part is steeper than 40% gradient, a cut-off that is not a published limit.
- Langmuir's figures and Tobler's formula were checked against Wikipedia only. The 1892 Naismith text was not opened.
- This is a planning tool, not safety advice. Tell someone your route, carry a map and warm clothing, and turn back if the plan slips.
Frequently Asked Questions
Sources & References
- Naismith's rule (Wikipedia). Read here in place of the original: Naismith W, "Excursions. Cruach Ardran, Stobinian, and Ben More", Scottish Mountaineering Club Journal 2(3):136, September 1892, which was not opened. Wikipedia contributors
- Route choice in mountain navigation, Naismith's rule, and the equivalence of distance and climb. Scarf P. J Sports Sci 25(6):719-726 (2007)
- Naismith's rule, Langmuir corrections section (Wikipedia). Read here in place of the original: Langmuir E, Mountaincraft and Leadership (1984; 4th ed. 2013, pp. 38-39, for the group pace), which was not read. Wikipedia contributors
- Tobler's hiking function (Wikipedia). Read here in place of the original: Tobler W, Three presentations on geographical analysis and modeling, NCGIA Technical Report 93-1 (1993, escholarship.org/uc/item/05r820mz), which was not opened. Wikipedia contributors
- Are Suggested Hiking Times Accurate? A Validation of Hiking Time Estimations for Preventive Measures in Mountains. Vecchiato M, Borasio N, Scettri E, Franzoi V, Duregon F, Savino S, Ermolao A, Neunhaeuserer D. Medicina (Kaunas) 61(1):115 (2025)
- Hiking-time formulas: a review. Prisner E, Sui P. Cartogr Geogr Inf Sci 50(4):421-432 (2023)
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Disclaimer: This calculator is for informational and personal journaling purposes only. It logs measurements and compares them to published reference values. It is not health, medical, or nutrition advice.