How to convert British National Grid references to latitude and longitude and what3words
British National Grid references are commonly used across Great Britain for mapping, planning, land, infrastructure and outdoor location work. But many digital mapping and navigation tools need latitude and longitude instead.
If you need to convert BNG to latitude and longitude, the what3words Coordinate Converter can help. It supports British National Grid, OS Grid References and WGS 84 latitude and longitude formats, including decimal degrees, degrees and decimal minutes, and degrees, minutes and seconds.
Why convert BNG to latitude and longitude?
British National Grid is a useful coordinate system for Great Britain, especially when working with national mapping references. But latitude and longitude is often needed when sharing locations with global mapping tools, GPS devices, navigation apps or systems that use WGS 84 coordinates.
That means you might need to convert BNG to latitude and longitude when:
- preparing site locations for a mapping platform
- sharing grid reference data with another team
- checking infrastructure or land records
- converting survey or planning data
- moving locations from a spreadsheet into another system
What format should you convert to?
For latitude and longitude in the decimal-degree format commonly accepted by mapping and navigation platforms, choose WGS 84 decimal degrees .
A decimal degree coordinate usually looks like this: 51.5072, -0.1276
Other systems may use degrees and decimal minutes, or degrees, minutes and seconds. The right format depends on where the coordinates will be used next.
Converting more than one grid reference
If you only have one coordinate to convert, a single conversion is enough. But if you are working with a list of sites, assets or locations, batch conversion can save time.
The what3words Coordinate Converter lets you convert coordinates individually or in batches. You can paste up to 100 coordinates, choose the input format, then convert them into WGS 84 latitude and longitude or another supported format.
You can also convert coordinates into what3words addresses, giving each location a simple three word address for a precise 3 metre square.