How Long Will a Hike Take? Naismith's Rule for Distance and Elevation Gain
October 29, 2026
Planning a hike means estimating how long it will take, so that you can start early enough, carry the right supplies, and be off the trail before dark. A simple method devised in 1892 by Scottish mountaineer William Naismith is still the standard starting point: allow one hour for every 3 miles (5 km) of horizontal distance, and add one hour for every 2,000 feet (600 m) of ascent.
For a 10-mile hike with 3,000 feet of elevation gain, the calculation is 10 ÷ 3 = 3.33 hours for the distance, plus 3,000 ÷ 2,000 = 1.5 hours for the climb, for a total of 4.83 hours, or about 4 hours 50 minutes. This does not include rest stops.
Skip the math and get your answer instantly:
Open the Speed Calculator →Applying the Rule
Step 1: measure the distance from a map or app. Step 2: total the elevation gain (ascent only) along the route. Step 3: apply 20 minutes per mile for distance and 30 minutes per 1,000 feet of climb. Step 4: add time for breaks, photography, and lunch. For a 6-mile hike with 2,000 feet of gain: 2 hours + 1 hour = 3 hours. For a 14-mile hike with 4,500 feet of gain: 4.67 + 2.25 = 6.9 hours.
Descents also matter. Gentle descents are fast, but steep descents slow most hikers, particularly with tired legs. Some versions add 10 minutes per 1,000 feet of descent for slopes steeper than 12 degrees.
| Hike | Distance | Ascent | Naismith time (no breaks) |
|---|---|---|---|
| Short loop | 5 miles | 500 ft | 1 h 55 min |
| Half-day hike | 6 miles | 2,000 ft | 3 h |
| Day hike | 10 miles | 3,000 ft | 4 h 50 min |
| Long day | 14 miles | 4,500 ft | 6 h 55 min |
| Summit push | 16 miles | 6,000 ft | 8 h 20 min |
Adjusting for You
Naismith's pace of 3 mph on flat ground suits a reasonably fit hiker carrying a light pack. Adjust it for your own speed: if you walk 2.5 mph on the flat, use 24 minutes per mile; if you walk 3.5 mph, use about 17 minutes per mile. Add 10% to 20% for a heavy pack, rough or snowy terrain, high altitude (above about 8,000 feet), hot weather, or large groups with slower members. Keep a record of your actual times on hikes to calibrate the rule for you. Fit hikers, trail runners, and those on well-maintained trails may be faster.
Tobler's hiking function is a more detailed model that gives speed as a function of slope: about 3.3 mph on a gentle downhill slope of around 5 degrees, 3.1 mph on flat ground, and falling to about 2 mph on a 10-degree uphill slope.
Daylight and Turnaround Times
Work backward from sunset. If sunset is at 6:30 p.m. and the hike takes 5 hours with breaks, start no later than 12:30 p.m. at the very latest, and preferably much earlier to leave a safety margin of at least an hour. For out-and-back hikes, set a turnaround time: if you have not reached the summit by, say, noon, turn back regardless of how close it seems. Carry a headlamp in case of delays. In winter, daylight is short and temperatures drop rapidly after sunset.
Energy and Water Planning
A hiker burns roughly 400 to 600 calories per hour with a pack on varied terrain, so a 5-hour hike uses 2,000 to 3,000 calories. Plan to eat 200 to 300 calories per hour, and drink about 0.5 liter per hour in moderate conditions, more in heat. Pack extra food and water beyond the estimate. Tell someone your route and expected return time, and check the weather forecast and trail conditions.
Frequently Asked Questions
What is Naismith's rule?
One hour per 3 miles of distance plus one hour per 2,000 feet of ascent.
Does Naismith's rule include breaks?
No. Add time for rest stops, meals, and photography.
How long does a 10-mile hike take?
About 3 to 3.5 hours on flat terrain, plus 30 minutes per 1,000 feet of ascent.
How do I adjust for a heavy pack or altitude?
Add 10% to 20% to the estimated time.
When should I turn back?
At a pre-set turnaround time, whatever your position, to leave margin before dark.