Grid Reference Formats

Grid references become more precise as you add more digits.

Basic Pattern

In the UK, a full grid reference is usually written as:

• two letters for the 100 km square
• then an equal number of digits for eastings and northings

Common Lengths

• 4-figure: general area within a 1 km square
• 6-figure: more precise location within a 100 m square
• 8-figure: more precise again
• 10-figure: very precise position

Reading Them Correctly

Read eastings first, then northings. A simple memory aid is "along the corridor, then up the stairs".

Formatting Options

Depending on your settings, OMN4 may show:

• prefix letters
• spaces between parts
• different precision lengths

Those formatting choices change how the reference looks on screen, but not the underlying position.