This simple tool helps make a rough estimate of the time you may take to complete a walk on typical Scottish hills, and the higher hills in England and Wales. It is based on my own personal experience, as a reasonably fit 33 year old hill walker, but you may need to make your own adjustments. The calcualtions for 'ideal' circumstances are very similar to those proposed by Eric Langmuir in Mountaincraft and Leadership (Scottish Sports Council, 1984), and used in The High Mountains (Irvine Butterfield, Diadem, London, 1993). Langmuir uses 3 miles per hour (I use 5 kmh) and 2000 vertical feet per hour (I use 600 m). These are, as noted by Butterfield, more strenuous that Naismith's rule (3 miles per hour and 1500 feet per hour). 

The calcualtions it works on are:

Total time = (Time horizontally  + Time vertically) x terrain factor x weather factor

Speed horizontally = 5 kmh, times being increased by a weather factor of 18 % for rain, and 55 % for snow / ice, and on top of one of these, 40 % for rocky ground, and 80 % for exposed scrambling.

Vertically, time is calculted on the basis of 600 metres per hour, or nearly 1000 feet per half hour, which some walkers may find hard going. These times are increased in exactly the same way as the horizontal times, for weather and terrain.

As noted, a terrain factor of 40 % increase in time is applied for rough conditions (anything worse than a smooth ridge walk in effect - an example might be The Five Sisters of Kintail, although parts of this towards the west particularly may be considered ideal walking) and 80 % for exposed / scrambly conditions such as one might find on the Aonach Eagach, Striding Edge, Cuillins etc. Clearly this is a simplification. Walks often contain difficult sections and easy sections. The user might want to use an averaging method in these circumstances

The weather and terrain factors mean, as an example, the Five Sisters of Kintail, with roughly 15 km horizontally and 1550 metres vertically (from GlenShiel Bridge to Loch Duich), takes 5 hours 34 if you consider the terrain 'ideal', or 7 hours 48 minutes if you consider it rocky (both in good weather) average - 6 hours 12 minutes. Rain makes the average 7 hours and 52 minutes, and in snow / ice the average is calculated as 10 hours and 22 minutes. This correlates fairly well with Butterfield, who quotes 6 - 9 hours.

Tell me what you think: mike@townsvillenet.com.au