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I'm trying to calculate route timings using the classic metric Naismith's Rule of 5kms or 600m per hour; ratio 1m ascent = 8.33m on the flat.

Using the formula distance X 1000 to turn total into metres, add ascent in metres, divide total by length of walk in minutes, divide that figure by the Naismith's ratio (8.33) should give an exact kms equivalent on the flat rate - ignoring rests and stops for lunch.

If I change the Uphill slider in Plotaroute to 8.33, and the 2 downhill and steep downhill slope adjustments to 0, then change the average flat speed rate to the exact pace I've already calculated I don't get anything remotely like this total time in Plotaroute. One example would be my calculation for my walk up Ben Oss and Dubhcraig last week. I reckon 19.4 kms distance +1215 metres ascent divided by time taken (399 mins) divided by Naismith's ratio 8.33 = a flat rate equivalent of 6.2 kmsm but entering 6.2 kms as the average flat speed rate, Plotaroute says the route should only take 4 hours 40 (280 mins)! Confused! What am I doing wrong? I'm trying to calculate a time within which I can return to a waiting coach with a good degree of reliability.

Any thoughts/input appreciated! My brain hurts!*? Being able to sort this would also enable me to calculate timings for route sections so as to be able to plan stops/ lunch breaks etc.

Cheers.

Hi Dave - the default settings for Walking are based on tbe Naismith parameters, where 7.92 units of distance is equivalent to 1 unit of climb, so you should just be able to use the defaults, altbhough you may want to adjust the average flat speed to suit your walking pace.

John