This utility finds central meridian for a given UTM zone. It takes into account existance of non-standard UTM zones in Norway and North Atlantic regions.
UTM Zone Finder Geodetic to UTM on Datum Geodetic to UTM on Different Datum Geodetic to UTM on Ellipsoid Geodetic to UTM on Custom Ellipsoid UTM to Geodetic on Ellipsoid UTM to Geodetic on Custom Ellipsoid UTM to Geodetic on Datum UTM to Geodetic on Different Datum