Lat Long to UTM Converter

What UTM does

UTM slices the world into 60 north-south zones, each 6° of longitude wide, and projects each one separately onto a flat grid. Because every zone is narrow, distortion stays small — and because the grid is in metres, distances and areas can be worked out with ordinary plane geometry rather than spherical trigonometry.

A position is given as a zone, an easting and a northing, both in metres.

The false origins

Eastings are measured from a line 500,000 m west of the zone's central meridian, so every easting inside a zone is positive and around 500,000. In the southern hemisphere northings start from 10,000,000 m at the equator and count down, again to keep the numbers positive. Those offsets are conventions, not distances from anywhere real.

Scale and convergence

The central meridian is deliberately scaled by 0.9996 so that distortion is spread across the zone rather than concentrated at the edges: the projection is slightly too small in the middle and slightly too large at the boundaries, with two lines of exact scale in between. The result keeps distortion under about 1 part in 1,000 anywhere in the zone.

Grid north and true north are not the same direction except on the central meridian. The grid convergence above is the angle between them — worth knowing if you are working from a compass bearing.

Limits

UTM covers 80°S to 84°N; the poles use the Universal Polar Stereographic projection instead. Zones 31V and 32V around Norway, and several around Svalbard, are irregularly sized by convention.

Coordinates here are on WGS 84, the datum GPS uses. A national grid such as OSGB36 or NAD27 is based on a different ellipsoid and can differ by tens to hundreds of metres, so never mix datums without a proper transformation.