Convert British National Grid (BNG) formerly known as the National Grid Reference (NGR) to latitude and longitude (lat/long WGS84) or vice versa.
See Using the National Grid from the Ordnance Survey for an explanation of how the BNG works.
Enter a British National Grid six figure number for both easting and northing to return decimal latitude and longitude.
For example, 429157, 623009 will return -1.54, 55.5
Enter decimal latitude and longitude to return a six figure number for both easting and northing of the British National Grid.
For example, -1.54, 55.5 will return 429157, 623009