What the Hiking Time Calculator does
This calculator estimates how long a walk or hike will take from its distance and the height you climb, using the rules walkers and mountain leaders have relied on for over a century: Naismith's rule, Langmuir's corrections for descents, a slower group pace, Tranter's corrections for fitness and Tobler's hiking function.
It shows every method side by side, builds a leg-by-leg plan with the arrival time at each point, adds your breaks, and checks the finish against the last light you enter. Each figure comes from a published rule of thumb, shown in the formulas below - not from tracking data or a prediction model.
How to use it
- Split the route into legs where the terrain changes - a climb, a ridge, a descent - and enter each as name, distance, ascent and descent. One line for the whole route also works.
- Choose the method for the plan. Naismith is the usual starting point; Tranter adjusts it for fitness; Tobler varies speed smoothly with slope.
- Choose your Tranter fitness: the minutes you take to climb 300 m over 800 m of distance at a steady pace. Tick the box to drop a level for a heavy pack, bad weather or rough ground.
- Add breaks as minutes per hour of walking plus fixed stops such as lunch, then a start time and the sunset or last-light time if you want the daylight check.
Reading the results
Moving time is walking only. Total time adds breaks, and it is the one to plan transport and daylight around.
The methods disagree on purpose. Naismith is simple and suits fit walkers on paths. Langmuir takes time off for gentle descents and adds it for steep ones. The group pace allows for mixed groups. Tobler is quicker on gentle ground and much slower on steep ground. The spread between them is a fair picture of the uncertainty.
Tranter's published table deliberately stops for long days at low fitness. Where a cell is empty, the calculator says so instead of inventing a value.
Worked example: a 15 km ridge day with 750 m of ascent
The route is 4 km to the ridge climbing 600 m, 5 km along it with 150 m up and 100 m down, and 6 km back to the valley dropping 650 m. That is 15 km with 750 m of ascent.
Naismith gives 15 / 5 = 3 hours for distance plus 750 / 600 = 1.25 hours for ascent: 4 hours 15 minutes of walking. Per leg that is 1 h 48 min, 1 h 15 min and 1 h 12 min.
The final descent averages about 6 degrees, inside Langmuir's 5 to 12 degree band, so Langmuir takes off 10 minutes per 300 m: 650 / 300 x 10 = about 22 minutes, giving 3 h 53 min overall. For a walker with a Tranter fitness of 25 minutes, 4.25 hours sits between the table's 4-hour (4.25) and 5-hour (5.5) columns: 4.25 + 0.25 x 1.25 = 4.56 hours, or 4 h 34 min.
With 10 minutes of rest per walking hour (42.5 minutes) and a 30-minute lunch, the Naismith day is 5 h 27.5 min, displayed as 5 h 28 min. Starting at 09:00 the group should finish at about 14:28, well before a 16:45 last light.
Formulas and scoring rules
- Naismith
hours = km / 5 + ascent m / 600- Langmuir descent correction
descent 5 to 12 degrees: -10 min per 300 m; steeper than 12 degrees: +10 min per 300 mEach leg's descent is assumed to be at a uniform angle over its share of the distance.- Group pace
hours = km / 4 + ascent m / 450- Tranter
look up the Naismith time in the fitness row; interpolate linearly between columnsColumns 2 to 24 hours; blank cells are reported, not filled.- Tobler's hiking function
speed km/h = 6 x exp(-3.5 x |slope + 0.05|); x 0.6 off pathSlope is rise over run; climbs and descents are taken at uniform grades.- Total time
moving hours + moving hours x break minutes per hour / 60 + fixed stops / 60
Limitations: what the result does not prove
- Every rule here describes an average walker in reasonable conditions. Snow, bog, scree, river crossings, poor visibility, navigation and group size can double the time.
- Children, older walkers and anyone carrying heavy loads should use the group pace or a lower Tranter fitness, and still allow a margin.
- The daylight check uses the times you enter. Check the forecast and local sunset, and remember that it gets dark earlier in valleys and forests.
- This is a planning aid, not safety advice. Tell someone your route, carry a map, a light and warm clothing, and turn back if the plan is slipping.
Privacy: where your data goes
Everything you paste, type or drop is processed in this browser tab. It is not uploaded, logged, stored or sent to analytics. Session recording and tag-manager scripts are switched off on this page.
Standards and sources
- Mountain Training - hill and moorland leader resources (route planning and timing)
- Mountaineering Scotland - planning your route and walking times
Frequently asked questions
What is Naismith's rule for walking time?
Proposed by William Naismith in 1892, it allows one hour for every 5 km of distance plus one hour for every 600 m of ascent (the imperial version is 3 miles an hour plus half an hour per 1,000 ft). It ignores descent and assumes a fit walker on reasonable ground.
How do I find my Tranter fitness level?
Time yourself climbing 300 m of height over 800 m of distance at a steady, sustainable pace. The minutes it takes - 15, 20, 25, 30, 40 or 50 - pick the row. If you do not know, 25 or 30 is a cautious choice for most leisure walkers.
Why is Tobler's hiking function faster than Naismith on flat ground?
Tobler's formula peaks at about 6 km/h on a slight downhill of around 3 degrees and gives about 5 km/h on the flat, then slows steeply on both climbs and descents. Naismith uses 5 km/h everywhere plus a fixed allowance for climbing, so the two diverge most on very flat or very steep ground.
Does walking downhill take longer or shorter than walking on the flat?
Gentle descents are usually quicker than the flat, which is why Langmuir takes time off for slopes of 5 to 12 degrees. On anything steeper people slow down to keep their footing, so Langmuir adds time back and Tobler's speed falls away sharply.
How many breaks should I allow on a day hike?
Many leaders allow 5 to 10 minutes per hour of walking plus a longer lunch stop. Groups, photographers and families usually need more. The calculator shows breaks separately so you can see how much of the day they take.
Can I use this for a multi-day trek?
Yes, one day at a time. Enter each day's legs separately, because Tranter's table and the daylight check are for a single day, and fatigue on later days is not modelled.
Last reviewed by the A2Z.Tools team against the sources listed above.
