Naismith’s Rule

Naismith’s Rule is a rule of thumb that helps in the planning of a walking or hiking expedition by calculating how long it will take to walk the route, including ascents. The rule was devised by William W. Naismith, a Scottish mountaineer, in 1892. The basic rule is as follows: Allow 1 hour for every 3 miles (5 km) forward, plus ½ hour for every 1000 feet (300 metres) of ascent.

A revised rule is 4Km /hour and then adding 1 minute for each 10m of height gained or 20m of descent.

Alternatively, Naismith’s Rule, allows an easy calculation of the time taken for a hill walk, for a reasonably fit and steady walker: 15 minutes for every kilometre of horizontal distance, plus 10 minutes for every 100 metres of ascent. The time should be calculated for the slowest person in a walking group. Corrections for descents:

Going gently downhill – 10mins / 300m of descent

Very steeply downhill + 10mins / 300m of descent