What is a 6-figure grid reference?

A 6-figure grid reference gives a location to 100m accuracy. It consists of 3 easting digits followed by 3 northing digits. Read the easting (left to right) first, then the northing (bottom to top). Remember: along the corridor, up the stairs.

How accurate is an 8-figure grid reference?

An 8-figure grid reference is accurate to 10m. A 10-figure reference is accurate to 1m. For mountain rescue, an 8 or 10-figure reference is preferred. GPS devices typically give 10-figure references.

What are the two-letter grid squares?

The UK National Grid is divided into 100km squares identified by two letters (e.g. NY for the Lake District, NN for the central Highlands). These letters prefix the numeric grid reference. A full reference like NY 215 065 identifies a unique 100m square in the UK.

CampCalcs

Grid Reference Calculator

Convert between 6-figure and 8-figure OS grid references with easting and northing.

Easting

5-digit easting value

Northing

5-digit northing value

How We Calculate This

The OS National Grid uses eastings (distance east) and northings (distance north) from a false origin southwest of the Isles of Scilly.

6-figure reference: First 3 digits of easting + first 3 digits of northing (100m accuracy)

8-figure reference: First 4 digits of easting + first 4 digits of northing (10m accuracy)

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify conditions and use proper safety equipment outdoors.