WGS84 to OSGB36 National Grid Coordinate Converter
Free online tool to convert coordinates from World Geodetic System 1984 (lat/lng) (EPSG:4326) to OSGB36 / British National Grid (EPSG:27700). Professional-grade accuracy using proj4, zero install, runs in your browser.
About WGS84
World Geodetic System 1984 (lat/lng) (EPSG:4326). The global reference system used by GPS, Google Maps and virtually all modern navigation. Defined by satellite geodesy and continuously refined.
About OSGB36 National Grid
OSGB36 / British National Grid (EPSG:27700). Ordnance Survey Great Britain 1936 datum — the national grid system for England, Scotland and Wales. Universally used in UK survey and cadastre.
Frequently Asked Questions
What is the difference between WGS84 and OSGB36 National Grid?
WGS84 (EPSG:4326) is geographic and based in Global, while OSGB36 National Grid (EPSG:27700) is national grid based in UK. The global reference system used by GPS, Google Maps and virtually all modern navigation. Defined by satellite geodesy and continuously refined. In contrast, ordnance survey great britain 1936 datum — the national grid system for england, scotland and wales. universally used in uk survey and cadastre.
Is this conversion accurate for surveying?
Yes. The conversion uses the industry-standard proj4 library with full datum shift parameters (). Typical accuracy is sub-meter for civilian applications. For cadastral precision, always verify against the official agency datum.
What coordinate format should I use?
For WGS84, enter coordinates as decimal degrees in the format "lat, lng" (e.g. 45.4642, 9.1900). The tool auto-detects the format.
Can I convert many points at once?
Yes, use our batch CSV converter. Upload a CSV with your points, select the transformation, download the converted file. Free with a SurveyingPedia account.
Is there an API?
Yes — call /api/v1/transform?from=EPSG:4326&to=EPSG:27700&coords=lat,lng for programmatic access. It returns the transformed coordinates as JSON.