From time to time people post to newsgroups asking how they can convert latitude and longitude to and from Maidenhead (QRA) locators and National Grid References (NGRs). So I've written this little page which does just that. It also tells you the distance and bearing from you to me.
All the maths is down to John Morris' excellent book, Amateur Radio Software.
Just fill in the form with your location. You can fill this in using lat/long, NGR or QRA locator and it will convert between them. It's reasonably clever at spotting just what you typed in. The only bit which needs explaining is how to enter lat/long.
You must put latitude first, either in degrees, minutes and seconds, or as decimal degrees. The hemisphere then follows (N/S), then longitude and (E/W).
For example you can enter your location as any of:
52.3958N 4.0417W
52'33'45N 4'2'30W
IO72XJ
SN 611 796
Note: It cannot handle place-names. It would be pretty impressive if it could, considering the size of the database it would need...
If you're interested, you can view the perl code for the conversion engine. You can also view the distribution of places converted on a map.