| OS Grid Ref: | SU123745 | |
| Latitude = | 51° 28.1' north | (51.4683882371116°) |
| Longitude = | 1° 49.4' west | (-1.82294964621862°) |
![[27K example]](/i/OSeg.gif)
Grid references are usually stored with an accuracy to around 100m within the United Kingdom. They consist of two letters, signifying a 100,000 metre square within which the point in question lies.
This is followed by six numbers - a three digit EASTING and a three digit NORTHING. The EASTINGS are the vertical lines on the OS map and the NORTHINGS are the horizontal lines on the map.
The first two digits of the three signify the 1000 metre square and the third digit specifies the point to the nearest 100 metres within the square.
The diagram illustrates this by way of an example.