Eastings and Northings grid references

A grid reference is a simple way of describing a location on the topographic maps supplied with your written permission. The grid squares seen on a map are made up of grid lines called Eastings and Northings. Each Easting grid line is numbered west to east and Northing grid line is numbered south to north.

Eastings are the vertical lines running from the top to bottom and divide the map from west to east.

Northings are the horizontal lines running left to right and divide the map from north to south.

Each easting and northing is numbered on the map margin at 1 km intervals; numbers are used to find a grid reference.

A position on a topographic map is generally shown as a four- or six-figure reference. A four-figure reference will identify which grid square (1 km x 1 km) contains your location. A six-figure reference will specify your position within 100 metres in that grid square.

Let’s search the map, and find the six-figure grid reference for Mount Arthur.

Find Mount Arthur on the map, locate the vertical grid line to the left of the map and record the two-figure Easting number in the top margin of the map: 26.

Divide the line into tenths, and estimate the value to give you a three-figure Easting number: 266.

Next, locate the horizontal grid line below your position, and record the two-figure number found in the left margin of the map: 77.

Divide the line into tenths, and estimate the value to give you a three-figure Northing number: 776.

Using the Easting grid first, your six-figure grid reference is:
GR: 266776