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Convert EPSG:27700 to EPSG:4326

Online coordinate converter from OSGB36 / British National Grid (EPSG:27700) to WGS 84 (EPSG:4326). Enter your source coordinates and get the result instantly. All transformations happen in your browser — no data is sent to any server.

Direct link to this transformation: epsgtransform.com/transform/epsg-27700-to-epsg-4326

Convert EPSG:27700 to EPSG:4326 in code

The same transformation with common GIS tools and libraries:

from pyproj import Transformer

transformer = Transformer.from_crs("EPSG:27700", "EPSG:4326", always_xy=True)
x, y = transformer.transform(-73.9857, 40.7484)
print(x, y)

Source: EPSG:27700 — OSGB36 / British National Grid

projected system measured in linear units (typically metres) · Area of use: UK - Britain and UKCS 49°45'N to 61°N, 9°W to 2°E

+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs +type=crs
More about EPSG:27700 →

Target: EPSG:4326 — WGS 84

geographic system using latitude and longitude on an ellipsoid · Area of use: World (by country)

+proj=longlat +datum=WGS84 +no_defs +type=crs
More about EPSG:4326 →

Frequently asked questions

How accurate is converting OSGB36 / British National Grid to WGS 84?
Projection-only conversions are accurate to floating-point precision. If a datum shift is involved, browser-based tools use Helmert parameters which are accurate to roughly 1-5 m; for surveying-grade work apply the official grid-shift transformation in a desktop GIS.
Does my data leave the browser when I use this converter?
No. All coordinate transformations are computed locally in your browser using proj4js. The coordinates you enter are never transmitted to any server.
Need the reverse? Convert EPSG:4326 to EPSG:27700 →