Coordinate Converter (Lat/Long, UTM, MGRS)
Convert latitude/longitude to UTM and MGRS and back, decimal degrees to DMS, and transform between EPSG coordinate systems.
UTM (zone, easting, northing)
17T 630084 4833438
- Easting
- 630084.31 m
- Northing
- 4833438.55 m
- Zone
- 17T — northern hemisphere · EPSG:32617
- MGRS
- 17T PJ 30084 33438
- Decimal degrees
- 43.642567, -79.387139
- Degrees, minutes, seconds
- 43° 38′ 33.24″ N, 79° 23′ 13.70″ W
WGS 84 datum. UTM/MGRS valid 80°S–84°N; MGRS digits are truncated (the reference names a square).
Show the work
Degrees, minutes, seconds to decimal degrees
deg = d + m ÷ 60 + s ÷ 3600 (S and W are negative)
43 + 38 ÷ 60 + 33.24 ÷ 3600 · −(79 + 23 ÷ 60 + 13.7 ÷ 3600) = 43.642567, −79.387139
Grid zone: 6° longitude strip, 8° latitude band
zone = ⌊(lon + 180) ÷ 6⌋ + 1 · band = letter number ⌊(lat + 80) ÷ 8⌋ of CDEFGHJKLMNPQRSTUVWX, from 0
⌊((−79.387139) + 180) ÷ 6⌋ + 1 · ⌊(43.642567 + 80) ÷ 8⌋ = 17T
Project onto UTM zone 17 (by proj4)
transverse Mercator, scale 0.9996, false easting 500,000 m
E 630084.31 m, N 4833438.55 m
Grid reference: whole metres, cut off (not rounded)
zone band ⌊E⌋ ⌊N⌋
17T ⌊630084.31⌋ ⌊4833438.55⌋ = 17T 630084 4833438
How it works
UTM and the other map projections are computed with proj4 (transverse Mercator on the WGS 84 ellipsoid for UTM). MGRS adds the 100 km square letters to the UTM grid and truncates — never rounds — the digits.
Datum: WGS 84 unless you pick another system. NAD83, ETRS89 and their UTM grids are treated as equal to WGS 84 (they differ by about 1–2 m today). British National Grid uses the 7-parameter Helmert shift EPSG:1314 (about 2 m), not OS's centimetre grid OSTN15. UTM and MGRS cover 80°S to 84°N; polar UPS zones are not supported. Projection strings: epsg.io.
Questions
- How does the coordinate converter work?
- UTM and the other map projections are computed with proj4 (transverse Mercator on the WGS 84 ellipsoid for UTM). MGRS adds the 100 km square letters to the UTM grid and truncates — never rounds — the digits.
- What does it assume?
- Datum: WGS 84 unless you pick another system. NAD83, ETRS89 and their UTM grids are treated as equal to WGS 84 (they differ by about 1–2 m today). British National Grid uses the 7-parameter Helmert shift EPSG:1314 (about 2 m), not OS's centimetre grid OSTN15. UTM and MGRS cover 80°S to 84°N; polar UPS zones are not supported. Projection strings: epsg.io.
- Why does MGRS truncate instead of round?
- An MGRS reference names a square, and its digits are the square's south-west corner. Rounding up could name the neighbouring square, so the standard (NGA, U.S. Army FM 3-25.26) truncates.
- Which datum is used?
- WGS 84 for lat/long, UTM and MGRS. Other systems in the list are converted through WGS 84 with their published EPSG parameters.
- What formats can I type?
- Decimal degrees (43.6426, -79.3871) or degrees-minutes-seconds with N/S/E/W (43°38′33.24″N, 43 38 33.24 N).
Related tools
- Astronomy (Distances) ConverterConvert astronomical distances — kilometers, astronomical units, light years and parsecs.
- SI Prefixes ConverterConvert between metric prefixes — from quecto (10⁻³⁰) to quetta (10³⁰).
- Sound (Bel, Decibel, Neper) ConverterConvert logarithmic level units — bels, decibels and nepers.
Want this on your site? Embed the coordinate converter (lat/long, utm, mgrs).