What is Naismith's rule?

Naismith's rule (1892) states: allow 5km per hour on the flat, plus 1 minute for every 10 metres of ascent. It was developed by Scottish mountaineer William Naismith and remains the standard for estimating walking time in the UK hills. It assumes reasonable fitness and good conditions.

How does fitness affect walking time?

Tranter's corrections adjust Naismith's time for fitness. A very fit hill walker may complete a route in 80% of Naismith's time. An unfit or inexperienced walker may take 150% of the predicted time. Carrying a heavy pack, poor weather and rough terrain all increase the time needed.

Should I add time for breaks?

Yes. A common rule is 10 minutes of rest per hour of walking. This calculator adds break time automatically. On longer days (6+ hours), people tend to take longer breaks, so factor in an additional 15-30 minutes for lunch.

Does descent reduce walking time?

Gentle descents (under about 12° gradient) are faster than the flat. Steep descents are slower and more tiring than flat walking. This calculator subtracts 1 minute per 20m of gentle descent, but very steep descents may actually add time.

CampCalcs

Walking Time Calculator

Estimate walking time using Naismith's rule with Tranter's corrections for fitness.

Distance

Distance measurement

Total Ascent

Total elevation gain

Total Descent

Enter the total descent

Fitness Level

Enter the fitness level

How We Calculate This

Naismith time = (Distance/5 × 60) + (Ascent/10) - (Descent/20) minutes

Adjusted time = Naismith time × Fitness factor

With breaks = Adjusted time + 10 min per hour

Fitness factors: Very fit (0.8), Fit (0.9), Average (1.0), Below average (1.25), Unfit (1.5)

Frequently Asked Questions

Related Calculators

Map Distance Calculator

Convert map measurements to real-world distances using your map scale.

Grid Reference Calculator

Convert between 6-figure and 8-figure OS grid references with easting and northing.

Bearing Calculator

Calculate the bearing between two grid references or coordinates.

Pace Counter Calculator

Calibrate your pace count for accurate distance measurement on foot.

Elevation Gain Calculator

Calculate total elevation gain and loss from a series of height points along a route.

Last updated: February 2026

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