how many miles are in a degree of latitude and/or longitude?
By definition one nautical mile equals one minute of latitude around the earth, so 1° of latitude contains 50 nm. One statute mile (sm) equals 1.1515 nm, so 1° of latitude equals 60 * 1.1515 or 69.09 sm. Longitude is a little trickier since the meridians of longitude all converge at the poles. You take the miles per degree of latitude and multiply it by the cosine of the latitude at which the longitude is measured to get the number of miles per degree of longitude (at that latitude).
