UTM Zones and EPSG Codes for WGS 84

Short answer

Every WGS 84 / UTM zone has a unique EPSG code, and the pattern is simple:

• Northern hemisphere: EPSG:326NN — for example, EPSG:32650 is WGS 84 / UTM zone 50N.
• Southern hemisphere: EPSG:327NN — for example, EPSG:32718 is WGS 84 / UTM zone 18S.

NN is the two-digit UTM zone number (01–60). All of these systems are projected, metre-based coordinate systems built on the WGS 84 datum — which is exactly what you want for measuring distance, area, and buffers. For background on what an EPSG code is, see what an EPSG code means in GIS; for when to use UTM at all, see WGS84 vs UTM.

What UTM actually is

UTM is not one projection — it is 60 separate transverse Mercator projections, one per zone, each optimized for a 6°-wide band. The transverse Mercator wraps a cylinder around a meridian rather than the equator, which keeps distortion small near that meridian and lets it grow outward. By restricting each zone to ±3° of its central meridian, UTM bounds the scale error to roughly 1 part in 2,500 at worst (about 0.04%), which is why it is good for measurement.

Each zone has fixed parameters:

• Central meridian at the middle of the zone (zone 33 → 15° E).
• Scale factor 0.9996 at the central meridian. This is deliberately set below 1 so the projection cuts the ellipsoid in two lines about 180 km either side of the central meridian; scale is slightly small in the middle and slightly large at the edges, spreading the error.
• False easting 500,000 m so easting values stay positive across the zone.
• False northing 0 in the north and 10,000,000 m in the south (so southern coordinates do not go negative below the equator).

So a coordinate like E 412,300 / N 5,648,900 in UTM 33N means 87,700 m west of the central meridian (500,000 − 412,300) and 5,648,900 m north of the equator.

How to find your UTM zone

1. Take the longitude (in decimal degrees) of your area of interest.
2. Compute zone = floor((longitude + 180) / 6) + 1. This gives a number from 1 to 60.
3. Choose the N code if your area is north of the equator, the S code if it is south.
4. Look up the EPSG code in the tables below.

Tip: each UTM zone is 6° of longitude wide. Data that spans more than one zone is usually better analysed in a single national or equal-area projection than forced into one UTM zone.

EPSG codes — Northern hemisphere (WGS 84 / UTM zone N)

EPSG codes — Southern hemisphere (WGS 84 / UTM zone S)

Most-looked-up zones

• EPSG:32650 — WGS 84 / UTM zone 50N (114°E–120°E): China, Philippines.
• EPSG:32718 — WGS 84 / UTM zone 18S (78°W–72°W): Peru, western South America.
• EPSG:32719 — WGS 84 / UTM zone 19S (72°W–66°W): Chile, Bolivia, western Argentina.
• EPSG:32632 — WGS 84 / UTM zone 32N (6°E–12°E): Germany, Italy, Nigeria.
• EPSG:4326 — WGS 84 geographic (latitude/longitude, degrees). Not a UTM zone; use it for storage and exchange, then reproject to the matching zone above for measurement.

Worked example: from longitude to reprojected data

Suppose your project area is centred near 13.4°E, 52.5°N (Berlin).

1. Zone = floor((13.4 + 180) / 6) + 1 = floor(32.23) + 1 = 33.
2. North of the equator, so use the N code: EPSG:32633 (WGS 84 / UTM zone 33N).
3. Reproject your WGS 84 geographic data into it. With GDAL:

ogr2ogr -t_srs EPSG:32633 sites_utm.gpkg sites_wgs84.gpkg   # vector
gdalwarp -t_srs EPSG:32633 -r bilinear dem_4326.tif dem_utm33.tif   # raster

In PostGIS, reproject a geometry already tagged as 4326:

SELECT ST_Transform(ST_SetSRID(geom, 4326), 32633) AS geom_utm FROM sites;

Now distances and areas (ST_Length, ST_Area, buffers) return metres, because EPSG:32633 is a metre-based projected system. The defining parameters of every northern UTM zone are a Transverse Mercator projection with scale factor 0.9996 on the central meridian, a 500,000 m false easting, and 0 m false northing; the southern zones add a 10,000,000 m false northing so that y-values stay positive below the equator.

The zone-boundary problem

Because each zone is its own projection, coordinates are discontinuous at zone edges. A point just east of the 12° E boundary has an easting near 800,000 in zone 32 but near 200,000 in zone 33. Two consequences:

1. You cannot mix layers from different zones in one analysis. Computing a distance between a zone-32 point and a zone-33 point using raw coordinates gives garbage. Reproject both into a single CRS first.
2. Projects straddling a boundary force a choice. If a project spans, say, 11°-14° E (zones 32 and 33), you can either:
   • reproject everything into one zone (e.g. all into 33N) and accept that points beyond the 3° half-width carry a little more distortion (still small — UTM tolerates a degree or two of overspill fine for most work), or
   • use a CRS designed for the wider extent: a national grid, a custom transverse Mercator with a central meridian at the project centre, or a Lambert Conformal Conic for E-W elongated areas.

For a survey-grade or large E-W project, a purpose-built CRS beats forcing UTM. For a compact site or a region that fits comfortably in one zone, UTM is ideal.

UTM vs Web Mercator vs national grids

• Web Mercator (EPSG:3857) is for tiled basemaps only. Its scale factor is 1/cos(latitude), so at 60° N distances are stretched ~2×. Never measure, buffer, or compute area in 3857.
• UTM is the general-purpose metric workhorse: conformal, metres, low bounded distortion, globally available.
• National grids (British National Grid EPSG:27700, ETRS89-LAEA EPSG:3035 for pan-European area work, US State Plane, etc.) are tuned to a country's extent and are usually the right choice when your data and clients already live there. ETRS89-LAEA, for instance, is equal-area and preferred for European statistical/area analysis where UTM's conformality is the wrong property.

Common pitfalls

• Assigning instead of reprojecting. Tagging data with a UTM EPSG code does not move the coordinates — it only relabels them. See assign CRS vs reproject.
• Using Web Mercator (EPSG:3857) for measurement. Web Mercator is for tiles, not distance or area. See why Web Mercator is not an analysis projection.
• Picking the wrong hemisphere. 326NN and 327NN differ only by the false northing; choosing the wrong one shifts data by 10,000 km.
• Forcing a multi-zone area into one zone. Distortion grows toward the zone edges; a dataset spanning several zones is better in a national or equal-area projection.

Sources

• EPSG Geodetic Parameter Dataset (epsg.org)
• epsg.io — search EPSG codes (e.g. EPSG:32633)
• GDAL gdalwarp
• GDAL ogr2ogr
• PostGIS ST_Transform