Detailed Route Planning

Detailed Route Planning

Planning your route in more detail will allow you to keep track of progress during the day

(©Crown copyright and database rights Ordnance Survey licence number 100054073 2013)
Detailed Route Planning 

Route Planning

From the high level view of whether the route distance is feasible for you, the group and within the time available, the next stage is to calculate a more detailed breakdown of each leg of the route. Do this by using one of the more precise methods, and taking care to use the correct linear distance for the scale of your map.

4mm = 100m on a 1:25,000 map
2mm = 100m on a 1:50,000 map

One grid square (horizontally or vertically) on an Ordnance Survey 1:25,000 or 1:50,000 map is equal to 1km.

Whilst we’re used to talking about miles in respect of road distances, the convention for hill walking is to quote kilometres, as maps are metric and the conversion to miles is and additional un-necessary step. (There are 0.6 miles in 1km if you want to convert back – 8km to 5 miles.)

Click here for the section on map scales.

Split the Route

Navigating the whole route in one go would be impossible, so splitting it into small manageable legs will mean that you can navigate it step by step. Each step should be no more than 1km, or about 15 minutes walking (on average). The end of each leg doesn’t have to be a named place on the map, it should be something easily identifiable in case of poor visibility, examples including; a path junction, track, bridge, start of a field boundary etc. If you follow the advice given in respect of Feature Tick Lists (within the Navigation section) such short sections would mean that you will never be more than approx 1km or 15 minutes from your last known position, thus making re-location easier if you become ‘lost’.

Time Taken

So the key question; how long each leg of the route take, thus giving a more accurate idea of time taken for the whole day and good intermediate points against which to measure progress. There are a number of different ways that you can calculate time, and it is a skill that will come with experience.

Naismith’s Rule

You may have heard of this one. William Naismith was a Scottish Mountaineer who stated:

Allow 1 hour for every 3 miles (5 km) forward, plus 30 minutes for every 1000 feet (300 metres) of ascent, for an average walker

...but depending on what you read and where, Naismith’s rule is 4km per hour.

The reality is that Naismith’s Rule is probably the minimum time required for any given leg of the walk.

Other Considerations affecting time taken:

  • General fitness
  • Speed of the slowest person
  • Number of people in the group – larger groups travel more slowly (they talk more)
  • The terrain – it’s rough, it’ll take longer (boulders, especially if wet, will take much longer)
  • How steep is the slope?
  • Wind speed and direction
  • Whether you use your hands on the walk
  • Fresh deep snow – feet sink – progress v slow
  • Take account of frequent but short stops


In case you hadn’t noticed, Naismith’s rule states 300m ascent in 30 mins, which equates to crossing one contour line per minute – quite a handy way of remembering it. But, you’ll also need to factor in the fact that you may zig-zag up a steeper slope, and that slope may look like, say, 100m on the map, but in fact it’s greater than that as the map can show only a plan, or bird’s eye view of the landscape.

What Naismith neglected to mention was how steep the slope was.

Take the following example from Lingmell Col to the summit of Scafell Pike, which is about 750m based on looking down on the map – plan view.

     ©Crown copyright and database rights Ordnance Survey licence number 100054073 2013

However, over that distance approx 220m will be gained, i.e. you cross over about 22 contour lines. Using a bit of maths we can work out that the actual distance on the ground is actually 781m, with an angle of just over 16°. So, not a massive increase, but certainly one to be aware of.

Using the 4km/h version of Naismith’s rule, that section of path would take about 12 minutes for the horizontal part (781m) and another 22 minutes for the vertical part, making a total of 34 minutes. Even if you didn’t allow for the extra 31 metres (which is overkill in this case), you’d arrive at about the same time estimate.

(If you’re a Lakes aficionado and think that that angle of 16° seems too shallow, remember that some parts of the climb will be flatter than others, but overall the angle is about 16°. Another way of looking at it is that a [modern] domestic staircase will be at an angle of 42° - much steeper.)


 If you want to have a play with some distances and heights gained, use this handy tool


On the way down, logic would say that you don’t need to make an additional allowance for the angle of the slope and that a horizontal allowance would be ok. Experience from others shows that a steep downhill section will in fact take longer than a flat section, but a shallow slope will take the same or less for the same horizontal distance. Whether you need to count contours for an estimate is perhaps too much, so experiment with a more simple method of using a multiplication factor of the horizontal distance. For example, walking down the same Scafell Pike slope as above, the 781m horizontal would take about 12 minutes. But, say you multiply the time by 1.5, giving 18 minutes, which may be a better estimate. You’ll work out your own pace, but that’s maybe a good one to start with.

Computer Software

There are a number of computer programs that can aid with planning routes, and even print a route card for you: