Precision and Accuracy of Data

Hospital Data: almost all of our hospital co-ordinates are stated to the nearest second of arc (e.g. 52°36’05” North) and comply with the WGS84 standard; this precision allows accuracy to within a 30-metre radius circle on the ground. Some large hospitals are 1,000 metres across, so where possible we state the co-ordinates of the maternity department (otherwise centre of the hospital complex).

Towns & Cities Data:  many of the GNIS co-ordinates that form a part of our Towns & Cities collection are only accurate to within 1m (1.6km) or so. To help those who are sticklers for precision, the local maps included on the latitude/longitude page will also show you (underneath the map) the exact co-ordinates of any place you choose to double-click on, enabling you to get precisely accurate data at street level.

Data Errors: most publicly-available gazetteers (including GNIS) have a significant percentage of slightly inaccurate records – plus a small percentage of records that are wildly inaccurate!  We have made a massive effort to eliminate any such faults from our site – you can help us by reporting any inaccuracies you come across here (simply double click on the correct location, optionally add name and email if you want an acknowledgement from us, then click ‘Report Inaccuracy’ under maps).

We are constantly updating and improving data.