Great Britain is covered by 100 x 100 km grid squares. Each grid square is identified by 2 letters. Birmingham and the Black Country straddles four of these squares: SJ, SK, SO and SP.
Each of these 100km squares are divided into 10km squares (e.g. SP08) which can be further subdivided to give more precise grid references (4, 6 or 8 figure grid reference)
For further information visit:
http://www.ordnancesurvey.co.uk/oswebsite/gi/nationalgrid/nghelp1.html
Calculating a Grid Reference for a Location
To get a 6 figure grid reference for a location:
Visit http://www.ordnancesurvey.co.uk/oswebsite/getamap/
Click on the large pink "I want to get a map now" button
Here you can search for a map by place name or postcode.
Click on the location you need a grid reference for (this will centre the map on that location).
A six figure grid reference will be displayed underneath the map
e.g. “Grid reference at centre - SP 054 858 GB Grid”
(You will only need to make a note of the “SP 054 858” part).
