Great Britain is broken up into a grid of squares, each one measuring 100km x100km. Each square has it’s own individual two letter reference prefix. The prefixes NH, NJ, NK, NN or NO are the ones applicable to NESBReC’s area.

These prefixes are found in the corners of OS maps. The squares are further sub-divided into 1km x 1km squares and even further into 100m x 100m squares. These subdivisions are depicted by numbers.

Quote the eastings (west to east) first then the northings (south to north). So, in the example here, the grid reference of the red square is NN613317 and the blue square is NN623308

Remember, think like a squirrel...
along the ground then up the tree!

For further help on how to work out a 6 figure grid reference click here or for a tutorial click on the image. http://www.ordnancesurvey.co.uk/oswebsite/gi/nationalgrid/nationalgrid.pdf

An extremely useful online tool is the GridRat tool

You can also utilise various sites to find and/or check your grid references such as: Multimap (www.multimap.com) and select OS Map; or Ordnance Survey (www.ordnancesurvey.co.uk/oswebsite/getamap)