Free Tool · Real-time Conversion
Coordinates converter — convert between DD, DMS, DDM, and UTM
Convert any GPS coordinate between Decimal Degrees, Degrees-Minutes-Seconds, Degrees-Decimal-Minutes, and Universal Transverse Mercator. Edit any field and the others update instantly. Free, no signup, runs entirely in your browser.
Convert coordinates
When you actually need to convert coordinates
For everyday use, your phone hands you decimal degrees and every app accepts them. The conversion problem only shows up when two systems disagree on format, and it shows up more often than you would think:
- Aviation flight plans usually require degrees-minutes-seconds. A modern smartphone reading needs translating before it can go into the flight planner.
- Marine GPS units typically display degrees-decimal-minutes. Cross-referencing a chart coordinate against your modern phone takes a quick DD ↔ DDM conversion.
- Land-survey documents and older maps almost always use DMS. Reading a deed or a topographic chart from before about 1995 and matching it to a modern satellite view is a DMS-to-DD job.
- Hiking and search-and-rescue work often uses UTM because grid distances map directly to meters on the ground. You can pace UTM offsets in a way you cannot pace decimal-degree differences.
- GIS pipelines and GeoJSON use (longitude, latitude) order, while Google Maps and consumer apps use (latitude, longitude). The tool above normalises the order; using the wrong order is the most common silent error in coordinate work.
- Emergency dispatch. Most dispatchers can take decimal degrees or DMS. Knowing which one you are reading off your phone matters more than the conversion itself — see our emergency GPS guide for the four-line script to say on the call.
Format quick reference
The same point on Earth in all four formats — useful as a calibration check the first time you use the tool:
| Landmark | DD | DMS | DDM | UTM |
|---|---|---|---|---|
| Eiffel Tower, Paris | 48.858420, 2.294500 | 48°51′30.3″N 2°17′40.2″E | 48°51.504′N 2°17.670′E | 31U 448262 5411917 |
| Statue of Liberty, NYC | 40.689247, -74.044502 | 40°41′21.3″N 74°02′40.2″W | 40°41.355′N 74°02.670′W | 18T 580757 4504699 |
| Sydney Opera House | -33.856785, 151.215290 | 33°51′24.4″S 151°12′55.0″E | 33°51.407′S 151°12.917′E | 56H 334893 6252053 |
| Mount Everest summit | 27.988100, 86.925000 | 27°59′17.2″N 86°55′30.0″E | 27°59.286′N 86°55.500′E | 45R 492588 3095886 |
How the tool handles each format
Decimal degrees are the master input. Type a value into either of the two top boxes and the page recalculates the DMS, DDM, and UTM versions on the fly. If you have the coordinate in DMS or DDM, type it in the corresponding row and the tool back-converts to decimal degrees. UTM is shown as a read-only output because typing easting and northing by hand is uncommon and error-prone — almost everyone who works in UTM already has it in a GIS file or a topographic chart.
For a deeper read on what each format actually represents and why anyone would use one over another, the decimal degrees guide zooms in on DD specifically, and the latitude vs longitude post covers signs, order, and the memory tricks.
How the UTM zone is calculated
UTM divides the world into 60 vertical zones, each six degrees of longitude wide. Zone 1 starts at the international date line and runs east. Your zone number is found from your longitude with the formula floor((lon + 180) / 6) + 1. Norway and Svalbard have hand-tuned exceptions to keep their countries from straddling zone boundaries, and the tool honours those special cases. The letter that follows the zone number — like the U in “31U” — comes from your latitude and identifies the eight-degree band you are sitting in.
Common mistakes the tool catches
- Latitude over 90 or longitude over 180 — the tool flags this rather than producing nonsense.
- Forgetting to switch the hemisphere letter when typing DMS for southern or western locations.
- Pasting a coordinate with the longitude first (a GeoJSON pattern). The tool assumes latitude first; if your map ends up in the ocean, swap the two.
- Mixing up DDM and DMS — they look similar but the trailing fraction is in different units. Type into the field labelled for the format you actually have.
Frequently asked questions
How do I convert decimal degrees to DMS?
Take the integer part of the decimal degree as the degrees value. Multiply the fractional part by 60 to get minutes (keep the integer part). Multiply the remaining fraction by 60 again to get seconds. Example: 48.8584° → 48° + (0.8584 × 60)′ = 48° 51.504′ → 48° 51′ (0.504 × 60)″ = 48° 51′ 30.24″. The tool above does this automatically as you type, including the hemisphere letter.
How do I convert DMS back to decimal degrees?
Take the degrees as is, divide the minutes by 60, divide the seconds by 3600, then add them all together. For southern latitudes or western longitudes, negate the result. Example: 48° 51′ 30.24″ N = 48 + 51/60 + 30.24/3600 = 48.8584°. Type either format into the tool above and the other recalculates in real time.
What is UTM and why would I use it?
Universal Transverse Mercator divides the world into 60 zones six degrees of longitude wide, each treated as a flat plane. Your position is expressed as "eastings" and "northings" in metres — so distances on a UTM grid translate directly to real-world metres on the ground. Hikers, search-and-rescue teams, surveyors, and the military prefer UTM for that reason. For everyday navigation, decimal degrees is far more common.
What does the letter after the UTM zone number mean (like "31U")?
The number is the longitude zone (1–60, six degrees wide). The letter is the latitude band (C–X, eight degrees tall, skipping I and O so they are not confused with 1 and 0). Together they uniquely identify which of the world's ~1,200 UTM cells you are in. The tool computes both from your input automatically and accounts for the Norway/Svalbard exceptions.
What is the difference between DMS and DDM?
Degrees-Minutes-Seconds (DMS) splits a degree into 60 minutes and each minute into 60 seconds — three units. Degrees-Decimal-Minutes (DDM) splits a degree into 60 minutes but expresses the remainder as a decimal — two units. Example: 48° 51′ 30.24″ in DMS becomes 48° 51.504′ in DDM. Marine GPS units typically display DDM; aviation and survey work usually use DMS.
My map ends up in the ocean off the coast of Africa — what is wrong?
You almost certainly pasted a (longitude, latitude) coordinate where the tool expected (latitude, longitude). GeoJSON, PostGIS, and most programming libraries put longitude first; Google Maps, Apple Maps, and most consumer apps put latitude first. Swap the two values and try again. A quick sanity check: if either number is greater than 90 in absolute value, that one must be longitude (|latitude| only goes up to 90).