**Timing**

This is based on knowing the speed at which you are walking and keeping a note of when you left your last known point.

Walking speed varies and is dependent on a range of factors including fitness, weight of rucksack, length of journey, wind, conditions underfoot and slope angle.

Distance | Speed | . | ||

Travelled |
5 kph |
4 kph |
3 kph |
2 kph |

1000 metres | 12 min | 15 min | 20 min | 30 min |

900 metres | 11 min | 13½ min | 18 min | 27 min |

800 metres | 9½ min | 12 min | 16 min | 24 min |

700 metres | 8½ min | 10½ min | 14 min | 21 min |

600 metres | 7 min | 9 min | 12 min | 18 min |

500 metres | 6 min | 7½ min | 10 min | 15 min |

400 metres | 5 min | 6 min | 8 min | 12 min |

300 metres | 3½ min | 4½ min | 6 min | 9 min |

200 metres | 2½ min | 3 min | 4 min | 6 min |

100 metres | 1 min | 1½ min | 2 min | 3 min |

50 metres | ½ min | ¾ min | 1 min | 1½ min |

Fig 3: Timing Chart. The timings have been rounded to the nearest ½ minute. Remember to add 1 minute for every 10 metres of ascent. |

A formula for estimating the time required for a journey was published in 1892 by the renowned Scottish mountaineer, W.W. Naismith. There are numerous variations on this formula and enthusiasts will discuss at length the merits of different models. However, useful estimates can be made without going into great detail and most people manage with just one or two versions of Naismith’s original calculations. The simplest formula combines the horizontal distance with the height gained. Allow 5 kilometres per hour on the flat plus 10 minutes for every 100 metres height gain.

Most reasonably fit people can maintain this speed throughout a day in the hills (provided there aren’t any particular difficulties) but remember that it doesn’t allow for rests or stops. “Naismith’s” is a valuable navigation aid and also a useful way of working out how long your entire route will take.

To use this formula for short navigation legs, break it down to 1.2 minutes per 100 metres horizontal distance and 1 minute for every 10 metres of ascent.

You can only travel at the speed of the slowest person and so you may need to use a slower formula such as 4 kph which is calculated at 1.5 minutes per 100 metres.

When going gently downhill, it is best to ignore the height loss and just use the horizontal component of the formula. When descending steep ground which will slow your rate of travel a rough estimate can be used – allow 1 minute for every 30 metres of descent, although this is only an approximation.

Using a Timing Chart (Figure 3) for the horizontal component makes the calculations easy although many people prefer to work it out mentally. Remember to add 1 minute for every 10 metres of ascent.

Working out timing calculations mentally becomes straightforward with practice:-

Measure the distance and allow 1.2 minutes for every 100 metres. An easy way to work this out is to use the 12 times table and move the decimal point forward. For example:-

300 metres 3 x 12 = 36 = 3.6 minutes

Round off to the nearest half minute = 3½ minutes OR

650 metres 6 x 12 = 72 = 7.2 minutes

Round off to the nearest half minute = 7 minutes

Add ½ minute for the extra 50 metres = 7½ minutes

On an O.S. 1:50,000 or 1:25,000 scale map, count the number of contours and allow a minute for every contour. Remember that every fifth contour is a thick line and so you can count the thick contours in multiples of five to work out the total height gain (on a Harvey Superwalker 1:25,000 scale map the contour interval is 15 metres and so you will have to work out the total height gain and then allow 1 minute for every 10 metres of ascent).

Add (a) and (b) together and you have an estimate of how long it will take to cover the ground.

Fig 4: From A to B (1083 metre spot height to the centre of the 1210 metre ring contour).

Image produced from the Ordnance Survey Get-a-map service. Image reproduced with kind permission of Ordnance Survey.

Figure 4 provides an example:-

From A to B

Distance 850 metres

850 metres = 8 x 12 = 96 = 9.6 minutes

Round off to the nearest half minute = 9½ minutes

Add ½ minute for the extra 50 metres = 10 minutes

Height gain 130 metres

(13 contours, including the one which encloses the 1083 spot height)

1 minute for every 10 metres (or for every contour if using this map) = 13 minutes

Total time from A to B = 10 + 13 = 23 minutes

None of this is of any use if you don’t have a watch. It is useful to have a stopwatch facility so you don’t have to remember the time at the start of each leg. Most high street jewellers sell inexpensive digital watches which have a stopwatch facility (about £13)