GPS and Latitude/Longitude are Not the same. Tvfool uses Latitude/Longitude. Here is one of many converters on the internet ,
http://www.csgnetwork.com/gpscoordconv.html.. However the best to do is go to the >>Start MAPS<< part of tvfool on the home page , move the pointer to your exact location , make the antenna height 25 feet and make a tvfool radar map.