GPS Coordinate Converter

Q: What does the letter after the UTM zone mean?

In 31U , U is the latitude band 48° N to 56° N . Some tools write the hemisphere instead 31 N . Band letters C to M are south of the equator and N to X north of it. If you type S after a zone, the tool checks whether band S 32° N to 40° N fits the northing, and otherwise reads it as the southern hemisphere.

Convert GPS coordinates between decimal degrees, degrees-minutes-seconds, decimal minutes, UTM and MGRS on the WGS84 datum, with Norway and Svalbard zones.

Coordinates (any format)

Paste latitude and longitude in decimal degrees, DMS or DDM (N/S/E/W letters or a minus sign), a UTM position (zone, band or hemisphere, easting, northing) or an MGRS reference. The format is detected automatically.

Examples:

Converted coordinates

Format	Value	Copy
Decimal degrees (signed)	–
Decimal degrees (N/S/E/W)	–
Degrees, minutes, seconds	–
Degrees, decimal minutes	–
UTM (zone + latitude band)	–
UTM (zone + hemisphere)	–
MGRS	–

MGRS precision

UTM zone details

Zone: –
Latitude band: –
Hemisphere: –
Central meridian: –
Easting: –
Northing: –
Scale factor: –

How to use the coordinate converter

Paste or type a position in the Coordinates (any format) field. The format is detected automatically: 48.8582, 2.2945, 48°51′29.5″N 2°17′40.2″E, N 48°51.4916′ E 2°17.6693′, 31U 448251 5411932 or 31U DQ 48251 11932 all work.
Read the same point in every notation in the Converted coordinates table, and use Copy on the row you need.
Choose the MGRS precision you want, from 1 m (10 digits) down to 10 km (2 digits).
Check the UTM zone details: zone number, latitude band, hemisphere, central meridian, easting, northing and the scale factor of the projection at that point.

Everything is calculated in your browser; the coordinates you enter are never sent anywhere.

The formats explained

Decimal degrees (DD): latitude and longitude as signed numbers, e.g. 48.858194, 2.294489. South and west are negative. Six decimals give about 11 cm of precision, which is more than any consumer GPS.
Degrees, minutes, seconds (DMS): one degree is 60 minutes and one minute is 60 seconds, e.g. 48°51′29.5″ N. This is the classic format of paper maps and nautical charts.
Degrees and decimal minutes (DDM): e.g. 48°51.4916′ N, used by many marine GPS units and geocaching sites.
UTM (Universal Transverse Mercator): the Earth is cut into 60 zones 6° wide. Inside each zone a point is given in metres: an easting (500,000 m on the central meridian) and a northing (distance from the equator, plus 10,000,000 m in the southern hemisphere). The zone is followed either by a latitude band letter (C to X, 8° each) or by the hemisphere (N or S).
MGRS (Military Grid Reference System): UTM with the easting and northing shortened by a pair of letters that name a 100 km square, e.g. 31U DQ 48251 11932. Fewer digits mean a bigger square: 4 + 4 digits locate a 10 m square.

How the conversion works

All positions are on the WGS84 ellipsoid, the datum of GPS. UTM is computed with the transverse Mercator projection using Krüger’s series (as published by Karney in 2011), with a scale factor of 0.9996 on the central meridian. This method stays accurate to well under a millimetre across a whole zone, much better than the older textbook formulas. MGRS square letters follow the current WGS84 lettering scheme.

The irregular zones are handled: southwestern Norway uses zone 32V (from 3° E to 12° E), and Svalbard uses only zones 31X, 33X, 35X and 37X. MGRS values are truncated, not rounded, as the standard requires, so a reference always names the square that contains the point. When you type an MGRS reference, the tool uses the south-west corner of that square.

Outputs use a dot as the decimal separator and the letters N, S, E and W so they can be pasted into GPS devices, mapping apps and spreadsheets.

Frequently asked questions

Why does my UTM easting differ by a metre from another tool?

Tools either round or truncate to the metre. This tool rounds UTM values and truncates MGRS values, as the MGRS standard requires. A difference of one metre is normal and comes only from this choice.

What does the letter after the UTM zone mean?

In 31U, U is the latitude band (48° N to 56° N). Some tools write the hemisphere instead (31 N). Band letters C to M are south of the equator and N to X north of it. If you type S after a zone, the tool checks whether band S (32° N to 40° N) fits the northing, and otherwise reads it as the southern hemisphere.

Can I convert coordinates near the poles?

Decimal degrees, DMS and DDM work everywhere. UTM and MGRS stop at 80° S and 84° N; the polar caps use the UPS grid, which this tool does not compute.

Are the coordinates from Google Maps WGS84?

Yes. Google Maps, OpenStreetMap and smartphone GPS all use WGS84 (or a datum within a few centimetres of it), so you can paste their coordinates directly.

How precise should my coordinates be?

Four decimals of a degree are about 11 m, five decimals about 1.1 m, six decimals about 11 cm. For hiking, an MGRS reference with 4 + 4 digits (10 m) is usually enough.