Conversion

To UTM / to lat/long

Choose which way the conversion is to go.

Lat/Long

Spheroid

The "spheroid" is the approximate shape of the earth.  Unless you know otherwise, use "WGS 1984" as this gives a good approximation worldwide.  Others may be closer in specific areas, but you should only use one of these if you know it's the right thing to do.

Latitude

The latitude entered as dd mm ss.sssN/S (N/S == north or south)

Longitude

The longitude entered as dd mm ss.sssE/W (E/W == east or west)

Lat/long<>degrees

Convert from latitude/longitude to decimal degrees.

UTM

Meridian

The meridian is the line of longitude near your location.  Usually it is an odd multiple of 3 degrees (e.g. -9, -3, +15 etc.) although, again specific areas and/or specific companies may be different.  Some companies use 0 degrees for their North Sea interests, for example

UTM north

The UTM north coordinate

UTM east

The UTM east coordinate

Southern hemisphere

Check if the location is in the southern hemisphere.

Note: UTMs are always positive,  regardless of whether the location is in the southern or northern hemisphere. 10 million is applied to the north component as appropriate.