Hiking Time Calculator

The Hiking Time Calculator estimates how long a trail will take using Naismith's rule and a set of practical refinements that experienced hikers rely on. Enter your distance and elevation gain and the tool works out a base time, then adjusts it with Langmuir descent corrections, a fitness factor, a pack-load penalty and rest breaks. You get a total hiking time, an arrival ETA, your average speed, a difficulty rating and an animated elevation profile.

What is Naismith's Rule?

Naismith's rule is a classic mountaineering formula devised by Scottish climber William Naismith in 1892. It gives a quick estimate of walking time on hilly ground: allow 1 hour for every 5 km (about 3 miles) of horizontal distance, then add 1 hour for every 600 m (about 2000 ft) of ascent. The rule assumes a fit walker on reasonable terrain and does not account for descents, rough ground, load or rest.

Naismith's Rule Formula

The base time is the sum of a horizontal component and a climbing component:

This calculator then multiplies the base time by your fitness and pack factors, applies the Langmuir descent correction, and adds a rest allowance to reach the final total.

Langmuir Descent Correction

Naismith's rule ignores downhill sections, but going down changes your speed. Eric Langmuir's widely used refinement adjusts for the descent grade:

On a gentle slope you can stride out and move faster than a flat walk, so time is saved. On a steep, technical descent careful footing slows you down, so time is added.

Average Hiking Speed Chart

Once climbing, terrain, load and breaks are included, real-world average speeds are lower than most people expect:

What Affects Your Hiking Time?

How to Use This Calculator

1. Enter the trail data: Choose metric or imperial units, then enter the trail distance and total elevation gain. Add the elevation loss for a descent correction.
2. Set your conditions: Select your fitness level, pack load, descent grade and planned rest breaks. Add a start time to get an arrival ETA.
3. Click Estimate Hiking Time: The tool applies Naismith's rule with the Langmuir correction and your adjustments.
4. Review the plan: Check your total time, ETA, average speed, difficulty rating, elevation profile, time breakdown and step-by-step calculation.

Frequently Asked Questions

What is Naismith's rule for hiking time?

Naismith's rule is a simple way to estimate walking time on hilly terrain. It allows 1 hour for every 5 kilometres (about 3 miles) of horizontal distance, plus an extra 1 hour for every 600 metres (about 2000 feet) of ascent. The two parts are added together to give the base time.

How accurate is Naismith's rule?

Naismith's rule gives a good baseline for a reasonably fit hiker on decent paths, but it assumes a steady 5 km/h pace and ignores fitness, load, rough ground, weather and fatigue. This calculator improves on it by adding Langmuir descent corrections, a fitness factor, a pack-load penalty and rest breaks, but any estimate should be treated as a guide, not a guarantee.

What is the Langmuir descent correction?

Langmuir refined Naismith's rule for downhill sections. On gentle descents of about 5 to 12 degrees you subtract 10 minutes for every 300 metres of descent because you move faster. On steep descents over 12 degrees you add 10 minutes for every 300 metres because careful footing slows you down.

Does Naismith's rule include rest breaks?

No. The original rule only covers moving time. Real hikes include stops for food, water, photos and navigation. This calculator lets you add a rest allowance of 5, 10 or 15 minutes per hour of moving time so the total is closer to your real day.

How do I account for a heavy backpack?

A heavier load slows both walking and climbing. This tool applies a pack-load penalty of about 8 percent for an overnight pack and about 18 percent for a heavy expedition load on top of the base Naismith time, which reflects the typical slowdown carrying extra weight.

What is a good average hiking speed?

On flat, easy ground most hikers average around 4 to 5 km/h (2.5 to 3 mph). Climbing, rough terrain, heavy packs and rest stops all reduce the average, so a hilly day hike often works out closer to 2 to 3 km/h overall once everything is included.

Additional Resources

• Naismith's Rule - Wikipedia
• Hiking - Wikipedia