Javascript is disabled on this browser.
Javascript must be enabled for this website to display and function correctly.

Grid Magnetic Angle Calculator

This is a grid magnetic angle request form. It will calculate the angle between grid north (British National Grid) and magnetic north at a given location.

Please note that it only outputs the correct grid magnetic angle for locations in Great Britain. Ireland uses the Irish National Grid.


Please enter your name and email address

Enter ONE ONLY of the following sets of coordinates:

British National Grid in metres:
Easting Value: (between 0 - 700000) Northing Value: (between 0 - 1300000)


British National Grid to nearest 100 m with prefix letters (see Ordnance Survey guide to giving a 6-figure grid reference):
Prefix: Easting Value: (between 0 - 1000) Northing Value: (between 0 - 1000)


Latitude and Longitude (in decimal degrees, longitude negative if west of Greenwich meridian):
Latitude: Longitude:


Your postcode in Great Britain:

Name of Location : (optional)

Include a Map of the Location : NO YES

To submit the query, press this button:

To clear the form, press this button: