WGS 84 → OS Grid Reference

Latitude and longitude to OS Grid Reference converter

Convert latitude and longitude to OS Grid References individually or in batches. Choose 6, 8 or 10 digits and see coverage and precision notes.

Batch coordinate converter

Enter one WGS 84 coordinate per line as latitude, longitude.

Input example: 51.5072, -0.1276

0 of 100 coordinates

The selected precision creates a 100 m, 10 m or 1 m cell.

Output example: TQ 30028 80380

Numeric coordinates are rounded for display: decimal latitude/longitude to up to 6 decimal places, metre-based coordinates to up to 3, DMS seconds to up to 2, and DDM minutes to up to 4.

About this conversion

Convert WGS 84 positions to OS Grid References made from a two-letter 100 km square and easting and northing digits.

Frequently asked questions

What input is accepted?

By default, enter WGS 84 latitude first and longitude second in decimal degrees. Select Reverse coordinate order to enter longitude first. Latitude must be from −90 to 90 and longitude from −180 to 180.

What output will I receive?

Choose 6, 8 or 10 digits for a 100 m, 10 m or 1 m cell. The reference identifies a cell rather than a single point.

Which axes and units are used?

WGS 84 input defaults to latitude then longitude in degrees. The OS Grid Reference output encodes British National Grid easting before northing.

How are precision and datum handled?

OSTN15 is required for the transformation. The selected 6-, 8- or 10-digit format determines a 100 m, 10 m or 1 m output cell; it does not improve source accuracy.

Where can I use this coordinate system?

Only positions within valid OS British National Grid coverage in Great Britain are supported.

What should I check?

  • Check that the selected latitude/longitude order matches each input row.
  • Use coordinates within Great Britain and the valid OSTN15 transformation area.
  • Choose 6, 8 or 10 digits to match the required grid-cell precision.

Is an OS Grid Reference a point or a cell?

It identifies a cell whose size depends on the selected number of digits.

What do 6, 8 and 10 digits mean?

They identify cells of 100 m, 10 m and 1 m respectively.