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I have a database with a list of address and their location as an East and North coordinate. An example is: East=431833 North=336684 Postcode=DE22 4LF

When I try to convert this address using this tool:

The result in longitude and latitude in Google gives me a location in Africa, not England where the address actually is.

Can anyone tell me which format the East and North coordinates are in and how to convert them?

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up vote 6 down vote accepted

Your coordinates are Ordnance Survey GB (OSGB36 Airy 1830 ellipsoid) 431833,336684 (base on a false origin with the Transverse Mercator projection.

To convert them correctly to Lat/Lng

Use this site:

example: look for the result in yellow Converts to 52.926628 -1.527923 (WGS84)

copy and paste into google maps,-1.5278&spn=0.00098,0.002792&sll=55.378051,-3.435973&sspn=15.177344,45.74707&t=m&z=19

You can also just use the postcode for google maps,-1.528076&spn=0.003919,0.011169&sll=52.926598,-1.5278&sspn=0.00098,0.002792&hnear=Derby+DE22+4LF,+United+Kingdom&t=m&z=17

Which returns the correct location - as is automatically geocoded into lat/lng coordinates

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@Mapperz---how did you know the CRS!? – elrobis Dec 4 '12 at 19:37
from experience – Mapperz Dec 4 '12 at 19:37
The presence of postcode is the tip, it seems. – elrobis Dec 4 '12 at 20:00

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