Naismith Rule Template
Naismith’s Rule is a rule of thumb that helps in calculating how long it will take to walk any route. The rule was devised by William W. Naismith, a Scottish mountaineer, in 1892. It is based on an average walking speed for a reasonably fit adult of 5km per hour (3 miles per hour,) plus a time allowance of 1 hour for every 600m (2000 ft) of elevation change, less a third of the total time for fit and experienced walkers.
It has since had many representations and modifications, to accommodate terrain and navigation difficulty or to modify the time adjustments, especially for descending. One version which has been used by the author is shown below. This formulation increases the time required for difficult terrain over a range of four terrain types, whilst reducing the extra time when descending as compared to climbing.
The example in the table is for a 24km trek on a bush track with easy navigation, with 500m of climb and 400m of descent, for fit and experienced walkers. The total time is estimated as 7.1 hours.