What is Naismith's Rule?

Naismith's Rule was devised by Scottish mountaineer William Naismith in 1892. It estimates walking time as 5 km per hour on flat ground plus 1 minute for every 10 metres of ascent. It remains the standard timing method used by mountain rescue teams, walking guides and navigation courses across the UK.

How accurate is Naismith's Rule?

On good paths with moderate fitness, Naismith's Rule is accurate to within 10-15%. It tends to underestimate time in poor conditions (rain, wind, boggy ground) and overestimate on well-maintained trails with fit walkers. Tranter's corrections adjust for fitness level and improve accuracy.

Does descent add time to a route?

Yes. Gentle descents (less than 12 degrees) are faster than flat walking, but steep descents (over 12 degrees) are slower. Rough, rocky descents require careful foot placement. This calculator adds a configurable penalty for descent, which accounts for the slowing effect of steep downhill sections.

How often should I plan rest stops on a hike?

A 10-minute break every hour is a good default for moderate fitness. Fitter walkers may prefer 5 minutes every 90 minutes. In hot weather or at altitude, more frequent short breaks are better than fewer long ones. Always plan a longer lunch stop on walks over 4 hours.

CampCalcs

Route Timing Calculator

Calculate hiking time from distance, ascent and terrain using Naismith's Rule.

Distance

Total route distance in kilometres

Total Ascent

Total metres of climbing

Total Descent

Total metres of descent

Terrain

Predominant terrain type on the route

Fitness Level

Your general walking fitness

How We Calculate This

This calculator uses Naismith's Rule with additional adjustments for terrain, fitness, descent and rest stops.

Naismith's Rule

Time = (Distance / Speed) + (Ascent / 10) minutes

Terrain speeds

Good path: 5.0 km/h
Moorland: 4.0 km/h
Rough ground: 3.0 km/h
Scramble: 2.0 km/h

Fitness adjustment

High: 1.0x, Moderate: 1.2x, Low: 1.5x. Applied to all time components.

Frequently Asked Questions

Related Calculators

Trip Budget Calculator

Calculate total trip costs including transport, accommodation, food and gear.

Campsite Cost Calculator

Calculate campsite costs per person per night with optional extras.

Mileage Calculator

Calculate driving distance fuel costs for getting to your campsite or trailhead.

Group Gear Splitter

Split shared group gear fairly based on individual pack weights and fitness.

First Aid Kit Calculator

Build a first aid kit checklist based on group size, trip length and remoteness.

Last updated: March 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.