Coordinate Converter

Convert latitude/longitude between Decimal Degrees (DD), Degrees-Minutes-Seconds (DMS), UTM, and MGRS formats. All calculations happen in your browser.

1.0.0
Version
Auth
Batch
Zero uploads. All conversions happen in your browser — no coordinates touch any server.
Try an example:

Decimal Degrees (DD) ± degrees, e.g. 40.7580, -73.9855

Degrees Minutes Seconds (DMS) 40° 45' 28.8" N, 73° 59' 7.8" W

UTM Universal Transverse Mercator — 18 T 585628 4511322

MGRS Military Grid Reference System — 18TWL8562811322

Coordinate Converter Tutorial

The Four Coordinate Formats

  • DD (Decimal Degrees) — what you see in Google Maps URLs. Simple floats. 40.7580, -73.9855
  • DMS (Degrees/Minutes/Seconds) — how old maps, aviation charts, and GPS receivers traditionally display it. 40° 45' 28.8" N
  • UTM (Universal Transverse Mercator) — used by topo maps, military, surveying. Divides the earth into 60 zones; each coord is a zone + easting + northing in meters.
  • MGRS (Military Grid Reference System) — extends UTM with a grid zone designator and 100km squares. Used by NATO militaries and SAR teams.

Common Use Cases

  • Copy a coordinate from one app into another that uses a different format
  • Convert aviation DMS charts into Google Maps DD for trip planning
  • Read military/topo UTM grid references from old paper maps
  • Share an MGRS location with rescue teams or hikers

Notes on Accuracy

UTM and MGRS use the WGS84 ellipsoid. Conversions round-trip losslessly to ~10 cm. Near the poles (above 84° N / below 80° S) UTM is undefined — use UPS (Universal Polar Stereographic) instead, which this tool does not handle.

DMS Input Tips

  • Use N/S and E/W for hemispheres
  • Negative DD lat = South; negative DD lon = West
  • DMS seconds can have decimals (e.g. 28.8")

Why In-Browser?

A coordinate can be sensitive (home address, dive site, trail crag). This tool runs entirely as JavaScript — your inputs never leave the page. Open DevTools → Network and hit submit; you won't see any requests go out.