National Grid (Britain)



On the streets of the UK's major cities, an address and a street atlas are probably all you need to locate places of interest. However a visitor intent on exploring rural parts England, Wales or Scotland will soon run up against the wide-spread use of national grid references. These are often found in guide-books, walking guides and even promotional leaflets, and usually look something like this:


 * [ SU921206 ], which is a location in the countryside just to the east of Midhurst, in West Sussex.

Most basic mapping in England, Wales and Scotland is undertaken by the Ordnance Survey. Maps published by the Ordnance Survey will certainly show national grid lines; most other maps are derived from Ordnance Survey mapping and will also probably show grid lines. This article is intended to explain how to locate a grid reference on a map using these grid lines. The Ordnance Survey created a PDF on understanding the national grid in Britain.

First select your map
Hopefully the information source that has given you the grid reference will also have suggested an appropriate map, or you will already have a map of the area in question.

If not, then try visiting the Ordnance Survey's Get A Map web site and entering the grid reference you have. This will show you a small map of the area, but it will also give you links to pages on various Ordnance Survey maps covering that area. Whilst the (not-so) hidden agenda of this site is to persuade you to buy the maps online, there is no requirement to do this; if you choose not to do so follow the links and note down the names of the maps you want. The most important information you need is the type and number of the map, for example:


 * Explorer 133
 * Landranger 144

Most good UK bookshops stock Ordnance Survey maps and shelve them by type and number. They can also be bought online.

The types of maps you are most likely to be interested in are the Landranger series (scale 1:50000) and the Explorer series (scale 1:25000). The former is best for exploring by car or bike, the latter for walking.

Although most street maps and atlases are not published by the Ordnance Survey, it is possible to locate a grid reference on most of them.