Naismith's rule
In walking or hiking, Naismith's Rule helps the planning of an expedition by calculating how long it will take to walk the route, including ascents and descents. The rule was devised by W.W.Naismith, a Scottish mountaineer in 1892.
5km per hour plus 1/2 hour for every 300 metres of ascent.
Corrections for short distances
- gently downhill -10 minutes per 300m of descent
- steeply downhill +10 minutes per 300m of descent
When walking in groups, it is important to calculate for the speed of the slowest person.
Tranter's Corrections
The following table reccommends adjustments to Naismith's Rule based on the "fitness" level of the individual. This is measured as the time it takes to climb 300m over a distance of 800m
| Individual fitness in minutes | Time taken in hours estimated using Naismith's Rule | |||||||||||||||
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 15 (very fit) | 1 | 1.5 | 2 | 2.25 | 3.5 | 4.5 | 5.5 | 6.75 | 7.75 | 10 | 12.5 | 14.5 | 17 | 19.5 | 22 | 24 |
| 20 | 1.25 | 2.25 | 3.25 | 4.5 | 5.5 | 6.5 | 7.75 | 8.75 | 10 | 12.5 | 15 | 17.5 | 20 | 23 | ||
| 25 | 1.5 | 3 | 4.25 | 5.5 | 7 | 8.5 | 10 | 11.5 | 13.25 | 15 | 17.5 | |||||
| 30 | 2 | 3.5 | 5 | 6.75 | 8.5 | 10.5 | 12.5 | 14.5 | ||||||||
| 40 | 2.75 | 4.25 | 5.75 | 7.5 | 9.5 | 11.5 | Too much to be attempted | |||||||||
| 50 (unfit) | 3.25 | 4.75 | 6.5 | 8.5 | ||||||||||||
The following conditions affect the "fitness" level
- 20kg load being carried - drop one fitness level
- Conditions underfoot - drop one or more fitness levels according to conditions
- Conditions overhead - drop one level for journey at night or if wind is against you