Depends where you are. Degrees Lat remains the same but Long. distance gets shorter as you near the poles. Should be easy enough to figure out on a GPS.
Mark your present position
Edit that position to a new one 1 degree E or W
GOTO that new pos. and you should have the long. dist.
repeat substituting N or S for part two and this will give you your deg. lat distance.
For my home position I get 69 miles between degrees latitude and 45.8 miles between degrees longitude.
I like to use the UTM coordinate system. If you can deal with metric, it is based on grid lines 1000 meters apart in both directions. Easier math for dummies like myself.
