Hiking Time Calculator: How Long Will My Hike Take?

What this hiking time calculator does

This hiking time calculator estimates how long a walk or hike will take from three numbers you can read off any map or route app: distance, total ascent and total descent. It uses Naismith's rule, the rule of thumb mountaineers and walking leaders have used since 1892, then adds your break time and a finish time so you can check you'll be back before dark.

Set your pace to match how you usually walk, choose whether to adjust for the descent, and enter how many minutes you rest each hour. The results update as you type.

How to use it

1. Distance: the total route length in kilometres. Use the figure from your map, GPS file or guidebook. For an out-and-back walk, include both directions.
2. Total ascent: the sum of all the climbing, in metres, not just the height of the summit above the car park. Route apps usually call this elevation gain.
3. Total descent: all the downhill in metres. On a loop this is usually close to the ascent.
4. Hiking pace: Relaxed, Average or Fit (see the table below).
5. Descent adjustment: leave it on classic Naismith, or apply Langmuir's correction for gentle or steep descents.
6. Break per hour of walking: minutes of rest for every full hour of moving time. Ten minutes an hour is a common planning figure.
7. Start time: the hour you set off, in 24-hour time. Use decimals for half hours, such as 8.5 for 08:30.

The calculator shows moving time, total time with breaks, finish time, the time spent on the climb, an effort distance (how far the route would be on flat ground for the same time) and average pace in minutes per kilometre.

The formula

The metric version of Naismith's rule is:

Time = distance ÷ 5 km/h + ascent ÷ 600 m/h

In other words, 12 minutes per kilometre plus 10 minutes per 100 m of ascent. The calculator scales both parts by your pace setting:

The relaxed setting is close to the group formula Langmuir later proposed, 4 km/h plus 1 hour per 450 m, which allows for the slowest member of a party.

Descent corrections

Naismith's original rule ignores downhill. Eric Langmuir's corrections, summarised on the Naismith's rule page, adjust for it:

If a route mixes both, pick the one that describes most of the downhill, or run the calculator twice and use the longer figure for planning.

Breaks and finish time

Breaks are added for each full hour of moving time. With the default of 10 minutes, a 3 hour 44 minute walk gets 30 minutes of breaks. Lunch stops, photo stops and summit time vary a lot, so raise the figure if you like to stop for longer. The finish time is simply start time plus total time.

Effort distance

Naismith's rule implies that 600 m of climbing takes as long as 5 km on the flat, so every 120 m of ascent counts as about 1 extra kilometre. Statistician Philip Scarf turned this into an equivalent flat distance, using a ratio of about 8 to 1. The calculator's effort distance shows how far your route would be on flat ground for the same time, which makes it easier to compare a hilly 12 km walk with a flat 20 km one.

Worked example

The default values describe a typical mountain day: 12 km with 800 m up and 800 m down at an average pace, starting at 08:00.

If most of the descent is steep and rocky, Langmuir's correction adds about 27 minutes (800 ÷ 300 × 10), and the total rises to about 4 hours 51 minutes once the extra break is included.

Quick reference: hiking time by distance and ascent

Moving time at the average Naismith pace, before breaks:

For a relaxed pace multiply by 1.25; for a fit pace multiply by about 0.83.

When to add more time

Naismith's rule assumes reasonable fitness, good paths and normal weather. It's best read as the minimum time for a route. Add time for:

These allowances are planning guides, not measured values. The best correction is your own history: compare your real times with the calculator on a few walks and adjust the pace setting until it matches.

Planning a safe hike with your time estimate

1. Check daylight. Look up sunset for the date and place. Your finish time should leave a buffer of at least an hour, more in winter and in the mountains.
2. Set a turnaround time. Decide in advance when you'll turn back if you haven't reached the top. A simple rule is to turn around at the time that would still get you down before your daylight buffer runs out.
3. Tell someone your plan. Share your route and expected finish time. The US National Park Service hiking safety guidance recommends planning ahead and leaving a trip plan.
4. Pack for the time, not the distance. Food, water and layers should match how long you'll be out. A 12 km walk with 1,000 m of ascent is a much longer day than a flat 12 km.
5. Check the forecast. Wind, heat and rain all slow you down and change what you need to carry. See the National Weather Service heat safety advice for hot-weather hiking.

Food and water for the time you'll be out

Once you know how long the hike takes, you can plan what to carry:

• Use the hiking calorie estimator to estimate energy burned for the distance, ascent and your body weight.
• Use the water carry calculator to work out how much water you need for the hours on the trail and the temperature.
• For snack ideas that keep you going on long climbs, see high-protein hiking snacks and day hike food ideas.
• For multi-day routes, combine daily times with the trail meal planner and the backpacking food weight calculator.

A rough rule many hikers use is to eat something every 60 to 90 minutes of moving time, and to drink little and often rather than waiting until you're thirsty.

Naismith vs other hiking time methods

Naismith's simplicity is the point: you can do it in your head with a map. Tobler's function and route apps model slope more finely, but they still don't know about your pack, the weather or the bog halfway up.

Common mistakes when estimating hiking time

1. Using summit height instead of total ascent. A ridge walk with several ups and downs can involve far more climbing than the highest point suggests.
2. Forgetting the return leg. Out-and-back distances double.
3. Not counting breaks. Two short stops an hour plus lunch can add an hour or more to a long day.
4. Planning on your best day. Use your normal pace, not the fastest walk you've ever done.
5. Ignoring descent on steep ground. Long, steep downhill on loose rock is slow and tiring on the knees.
6. Mixing units. If your map uses feet, divide by 3.28 to get metres before entering ascent.

Converting from miles and feet

The original rule, 1 hour per 3 miles plus 1 hour per 2,000 feet, is effectively the same as the metric version used here.

Limits of this calculator

• It assumes a steady walking pace and doesn't model each slope separately.
• Breaks are added per full hour of moving time; a 55-minute walk gets no break added.
• The descent corrections are simplified to one type for the whole route.
• It's not designed for scrambling, climbing, ski touring or trail running.
• It can't account for weather, route-finding or how you feel on the day.

Treat the result as a planning number and keep a margin. If the estimate leaves you finishing close to sunset, choose a shorter route or start earlier.

Frequently used figures

Sources: Naismith's rule, including Langmuir's corrections and Scarf's equivalence; US National Park Service, hiking safety; National Weather Service, heat safety.