FOUR-FIGURE GRID REFERENCES

COORDINATES

FOUR-FIGURE GRID REFERENCE

A four-figure grid reference describes the location of a point of interest in a 1 km x 1 km square on a 1:25000 topographic map and consist of four numbers.

For instance GR (Grid Reference) 54 72 means that the feature is located in the grid square with an easting value of 54 and northing value of 74.

Four-figure grid references are useful to locate a feature on a map when location accuracy is not important.

READING A FOUR-FIGURE GRID REFERENCE OFF A MAP

Let’s get the four-figure grid reference of spot height 394 located between the words Dawes and Ridges.

    1. Locate the grid square in which spot height 394 is located.
    2. Locate the bottom left corner of the grid square: this is the four-figure grid reference for spot height 394.
    3. At the bottom left corner, follow the vertical line (easting) up or down until you can read the easting value (large number) on the map: 69.
    4. At the bottom left corner, follow the horizontal line (northing) left or right until you can read the northing value (large number) on the map: 75.
    5. The four-figure grid reference for spot height 394 is: GR 69 75 on the Springwood topographic map – 2017 edition.
1:25000 Springwood topographic map - 2017 edition
Let's find the four-figure grid reference of spot height 394.
Find the grid square in which spot height 394 is located.
Locate the bottom left corner of the grid square: this is the four-figure grid reference.
Follow the easting (vertical) line until you can read an easting value.
Read the easting value on the map: 69.
Follow the northing (horizontal) line until you can read a northing value.
Read the northing value on the map: 75.
The four-figure grid reference for spot height 394 is GR 69 75.
Previous
Next
TIP

The easting line labelled: 270000mE means that easting line 70 is 270000 m (270 km) East from a given origin.

The northing line labelled: 6275000mN means that northing line 75 is 6275000 m (6275 km) North of a given origin.

The smaller digits are dropped on the edges of the map. For example easting line 269000mE is written 69 and northing line 6276000mN is written 76.

PLOTTING A FOUR-FIGURE GRID REFERENCE ON A MAP

Let’s find the four-figure grid reference 74 64 on the Springwood topographic map.

  1. Find the vertical easting line 74 on the map: it is to the left of easting line 75 as easting numbers increase from left to right (or west to east).
  2. Find the horizontal northing line 64 on the map: it is below northing line 65 as northing numbers increase from bottom to top (or south to north).
  3. Locate the intersection of easting line 74 and northing line 64. this is the four-figure GR 74 64.

The grid reference for the 24 m, 65 m and 40 m cliff lines, the intersection of the Victory track and the Martin Falls track is 74 64.

1:25000 Springwood topographic map - 2017 edition
Find the vertical easting line 74.
The red line is easting line 74.
Find the horizontal northing line 64.
The blue line is northing line 64.
Locate the intersection of easting line 74 and northing line 64.
The intersection of the lines is GR 74 64.
Previous
Next

A four-figure grid reference is not useful to locate a person or an object. A six-figure grid reference is more accurate for that task!

Learn about six-figure grid reference here!

IN SUMMARY

On a 1:25000 topographic map, a four-figure grid reference is the coordinate of  the bottom left corner of a grid square printed on the map when accuracy is not needed.

Four-figure grid references refer to a 1 km x 1 km square which is sufficient to locate features on a map.

Always specify which map you are using: for instance Springwood topographic map.

BACK TO NAV CORNER