JoseFitani
🧭 Coordinate Converters

Coordinate Format Converter

Convert between decimal degrees, DMS, DMM, UTM, MGRS, Plus Codes and more.

This page explains how the coordinate format converter works, the data and formulas behind it, and how to interpret the result. Coordinate conversions are exact to machine precision; the only source of error is the precision of the input. All formats describe the same location - the notation just differs. The tool is one of 329 free, open tools on JoseFitani for maps and geography. It runs in your browser with no sign-up needed. Use the search field or click the map to drop a pin - the tool uses standard mathematical formulas for each format, all based on the WGS84 datum (EPSG:4326) and returns the result in seconds. Below you'll find a step-by-step guide, real use cases, the methodology, FAQs, and data sources.

Decimal Degrees
48.858400°, 2.294500°
Degrees Minutes Seconds
48° 51' 30.24" N, 2° 17' 40.2" E
UTM
31N 448252E 5411955.03N
MGRS
31UDQ 48252 11955
Plus Code
8FW4V75V+9R

MGRS is derived from the WGS84 ellipsoid series used on this site (accurate to a few metres) — suitable for reference and education, not for survey-grade work. Plus Codes follow the Open Location Code specification.

How to use this tool

1
Enter your input

Type your query, paste coordinates, or click on the map. The tool uses standard mathematical formulas for each format, all based on the WGS84 datum (EPSG:4326) to process your input locally in the browser.

2
View the result

The result appears instantly with the map showing your location. You can adjust by clicking elsewhere or searching a new place.

3
Copy or share

Click Copy to save to clipboard, or Share to send a direct link with the exact inputs.

What people use this tool for

Feeding coordinates to a GPS device

Hikers and sailors often find coordinates online in decimal degrees while their handheld GPS expects degrees-minutes-seconds. Converting between the formats avoids the classic error of typing a decimal value into a DMS field, which can put you kilometres off. A quick conversion before the trip keeps the device and the plan in agreement.

Example: A hiker converts a summit's decimal coordinates into DMS to enter them into an older Garmin that only accepts degrees, minutes, and seconds.
Reporting positions to emergency services

In an emergency, callers may only have a Plus Code or a what3words-style reference from their phone while rescuers work in UTM or MGRS grids. Converting the caller's format into the rescuers' grid system removes a dangerous translation step under pressure. Every minute saved in locating someone matters.

Example: A dispatcher converts a lost walker's Plus Code from their phone into an MGRS grid reference for the mountain rescue team already working off military maps.
Cleaning data for GIS projects

Analysts merging datasets often find coordinates mixed across formats — one spreadsheet in DMS, another in UTM, a third in decimal degrees. Converting everything to a single format, usually decimal degrees, is the unglamorous first step before any mapping works. Skipping it produces points plotted in the wrong hemisphere.

Example: A researcher standardises a decade of field records from DMS into decimal degrees before importing them into QGIS for a habitat study.
Decoding coordinates from old documents

Historians, surveyors, and property researchers encounter coordinates in legacy formats in old deeds, military records, and expedition logs. Converting MGRS or old grid references into modern decimal degrees lets those locations be found on today's maps. It bridges the gap between paper archives and digital mapping.

Example: A local historian converts an MGRS reference from a 1980s army survey map into decimal degrees to locate a forgotten boundary marker.

How it's calculated

Supports all common formats used in navigation, GIS and geocaching.

The calculation runs in your browser - no data is sent to our servers. Map tiles come from OpenStreetMap (ODbL license), geocoding uses Nominatim (1 request/second limit), and elevation uses the Open-Elevation API backed by SRTM data. All are free, open services.

All calculations use the WGS84 datum (EPSG:4326), the same as GPS. For other datums (NAD27, NAD83, ETRS89), a separate conversion is needed. The difference is typically under 1 metre - negligible for most uses but important for survey-grade work.

The formulas match those in professional GIS software (QGIS, ArcGIS, Global Mapper), just in a browser-friendly form. For sub-metre accuracy, use professional software with ellipsoidal calculations. Results are shown in multiple units: km and miles for distance, km²/m²/hectares/acres for area, metres and feet for elevation. Conversion factors are exact (1 mile = 1.609344 km), so the only error source is input precision.

Related tools and resources

For more tools in this category, explore the related tools listed below. Each tool includes full documentation, examples and FAQs. Explore related tools in our Coordinates category for complementary functionality. See the Tools index for all 329 tools, or read our blog for in-depth articles on geography and maps.

Frequently asked questions

What is DMM?

Degrees Decimal Minutes - a hybrid between DD and DMS.

What is the difference between DD, DMS, and DMM?

DD (decimal degrees) writes coordinates as a single decimal number, like 51.5074°. DMS (degrees-minutes-seconds) splits each degree into 60 minutes and each minute into 60 seconds. DMM (degrees-decimal-minutes) is the middle ground: whole degrees plus decimal minutes. They all describe the same point; only the notation differs.

What are UTM coordinates?

UTM (Universal Transverse Mercator) divides the world into 60 zones and gives positions in metres east and north within a zone, like 500000 m E, 4649776 m N in zone 33N. Because the units are metres, distances are easy to estimate by subtraction. Hikers, surveyors, and militaries favour it for fieldwork.

What are MGRS grid references?

MGRS (Military Grid Reference System) is built on UTM but adds letter codes so a position reads as a compact alphanumeric string. More digits mean more precision — a 10-digit reference pins a point to about a metre. It is the standard grid for NATO militaries and appears on many topographic maps.

What are Plus Codes?

Plus Codes (Open Location Code) are short alphanumeric codes that represent an area, like 9C3XGV4F+5W, designed to work where street addresses do not exist. They are free, open, and usable offline once generated. Delivery and emergency services increasingly accept them as address substitutes in unaddressed areas.

Which format should I use with Google Maps?

Google Maps accepts decimal degrees most reliably — paste them as latitude, longitude and it drops a pin. It also understands DMS if formatted clearly. For sharing a location with someone, decimal degrees or a Plus Code are the least error-prone choices.

Does converting between formats lose precision?

Conversion itself is mathematically exact, but rounding during display can shave off precision. Six decimal places in decimal degrees pin a point to about 10 cm, which exceeds what most sources provide. If your input was only precise to a minute of arc, no conversion can invent the missing precision.

Why do my UTM coordinates need a zone number?

Because the same easting and northing values repeat in every one of the 60 UTM zones — without the zone, the coordinates are ambiguous across the planet. Always record the zone (and hemisphere letter) alongside the numbers. A coordinate pair without its zone is an incomplete address.

Can negative coordinates be converted?

Yes. Southern latitudes and western longitudes are negative in decimal degrees, and the converter handles the sign correctly into DMS, UTM, and the other formats. The most common mistake is dropping the minus sign when copying, which mirrors your point across the equator or prime meridian.

Data sources & methodology