QUESTION: I often do walks that turn out to be too ambitious. Is there any ‘easy’ way to assess a route’s timings?
ANSWER: ROB JOHNSON MIC
A qualified International Mountain Leader, Rob’s led groups all over the world via his company www.expeditionguide.com
"The traditional way of calculating how long a route will take is to use Naismith’s Rule. The basic rule says ‘Allow 1 hour for every 3 miles (5km) forward, plus 1 minute for every 10m of height gained’. On OS maps with contour lines at 10m intervals this means the ascent can be calculated by adding one minute per contour. You may find you actually walk a bit slower or maybe quicker than 5km an hour, so you need to allow for this in your calculations. A tip is to carry a timings card [left] that will give you the time taken at different speeds, to save doing the maths on the hill. You can make your own, or Google will produce a few different formats!
Even easier still is to use a piece of route-planning software to plan your route, and work out the total ascent and timings for you. There are examples from Anquet, Memory-Map and ViewRanger, and many can be used as part of a navigation aid on your smartphone or GPS too. The Ordnance Survey website has a free route-planning tool on its ‘OS Maps’ page: see www.ordnancesurvey.co.uk/osmaps To the time calculated to cover the distance of your route don’t forget to add in some rests to enjoy the view or have some lunch. In the winter allow a bit of time before sunset to get back off the hill before it goes dark. Route-planning is a big part of the fun, so enjoy it!