Coordinate converter

Convert British National Grid (BNG) formerly known as the National Grid Reference (NGR) to latitude and longitude (lat/long WGS84) or vice versa.

See The National Grid FAQs for an explanation of how the BNG works.

This coordinate converter uses the Oracle Spatial 10g coordinate transformations using approved (recommended) EPSG codes for BNG, WGS84 and ETRS89, which are 27700, 4326 and 4258 respectively. Technical details can be provided on request.

Bulk conversion

Due to popular demand, we have now published a guide for bulk conversion of coordinates.

Convert BNG to lat/long

Enter a British National Grid six or seven figure number for both easting and northing to return decimal latitude and longitude.
For example, 429157, 623009 will return -1.54, 55.5 WGS84 (SRID 4326)

Convert lat/long to BNG

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 WGS84 (SRID 4326) will return 429157, 623009

Decimal lat/long

Degrees, minutes and seconds for lat/long



Convert using a web service

BNG to Lat/long

To convert BNG to lat/long, use this URL:[six figure number]&northing=[six figure number]


Lat/long to BNG

To convert decimal lat/long to BNG, use this URL:[decimal latitude]&lon=[decimal longitude]


To convert degrees, seconds and minutes to BNG, use this URL:[latitude in degrees]&lngMinutes=[longitude in minutes]&lngMinutes=[longitude in seconds]&latMinutes=[latitude in minutes]&latMinutes=[latitude in minutes]&latMinutes=[latitude in seconds]