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

DD (Decimal Degrees) expresses latitude and longitude as a single decimal number, e.g. 40.7128, -74.0060. DMS (Degrees Minutes Seconds) breaks it into three parts: 40° 42' 46.08" N, 74° 0' 21.6" W. DDM (Degrees Decimal Minutes) uses degrees and decimal minutes: 40° 42.768' N, 74° 0.360' W. DD is used in most digital/web mapping systems. DMS is traditional navigation and many GPS units. DDM is common in aviation and marine charts.

What is UTM and when is it used?

UTM (Universal Transverse Mercator) is a metric coordinate system that divides the Earth into 60 zones, each 6° of longitude wide. Instead of angles, UTM gives you meters east and north from a reference point within each zone. It's widely used in surveying, military, and GIS applications because it minimizes distortion within each zone and makes distance calculation straightforward.

Geohash is a hierarchical spatial encoding that converts a latitude/longitude pair into a short alphanumeric string. The longer the string, the more precise the location. Geohashes are useful for proximity searches in databases and APIs — points with the same geohash prefix are geographically close to each other. The 8-character hash in this tool gives precision of about 19 meters.

How accurate is the distance calculation?

The distance calculator uses the Haversine formula on a spherical Earth model with a mean radius of 6,371.0088 km. This is accurate to within about 0.5% for most distances. For very long distances or precision surveying work, use the Vincenty formula on the WGS84 ellipsoid, which accounts for Earth's flattening and is accurate to within 0.5mm.

Lat Long Converter — DD, DMS, DDM, UTM, Geohash + Map & Distance

What This Tool Does

Everything you need to work with geographic coordinates — convert, visualize, and measure.

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All major formats

Convert between Decimal Degrees (DD), Degrees Minutes Seconds (DMS), Degrees Decimal Minutes (DDM), UTM, and Geohash in one step.

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Map preview

Visualize any coordinate on an embedded OpenStreetMap. Adjust zoom level. Open directly in Google Maps or OpenStreetMap with one click.

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Distance calculator

Calculate great-circle distance between two coordinate pairs using the Haversine formula. Results in km, miles, nautical miles, meters, and feet.

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Bearing & midpoint

Get the initial compass bearing from Point A to Point B and the geographic midpoint — both shown alongside the distance result.

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One-click copy

Copy any output format — DD, DMS, DDM, UTM, Geohash — to clipboard instantly with the copy button next to each result.

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Direct map links

Every conversion generates a Google Maps link and OpenStreetMap link for the exact coordinate, opening in a new tab.

How to Use This Tool

1

Choose your input format

Select DD (Decimal Degrees), DMS (Degrees Minutes Seconds), or DDM (Degrees Decimal Minutes) from the tabs in the Converter section — whichever matches your source data.

2

Enter coordinates

Type in your latitude and longitude values. For DD: use negative values for South/West. For DMS and DDM: use the direction dropdowns (N/S and E/W). Press Enter or click Convert.

3

Read all output formats

Results show DD, DMS, DDM, UTM, and Geohash simultaneously. Click any Copy button to copy that specific format to your clipboard.

4

Preview on map

Click "Preview on map" under the results, or switch to the Map Preview tab and enter coordinates manually. Adjust the zoom level and open in Google Maps or OSM.

5

Calculate distance

Switch to the Distance tab. Enter two coordinate pairs (in decimal degrees). Click Calculate Distance to get the great-circle distance, bearing, and midpoint.

6

Copy or share results

Use the copy buttons on any result card. Open either map service link to share the exact location. Bearing is shown as both degrees and compass direction (NNE, SW, etc.).

Logic Behind the Tool

How the math works for each conversion and distance formula.

DD ↔ DMS conversion

To convert DD to DMS: degrees = floor(|DD|), minutes = floor((|DD| − degrees) × 60), seconds = ((|DD| − degrees) × 60 − minutes) × 60. Direction is N/E if positive, S/W if negative. Reverse applies the inverse: DD = D + M/60 + S/3600, then negate for S or W.

UTM projection

Universal Transverse Mercator divides Earth into 60 zones of 6° each. The tool computes approximate easting and northing using the WGS84 ellipsoid parameters (a = 6,378,137 m, f = 1/298.257). Northing adds 10,000,000 m for Southern Hemisphere coordinates to keep values positive.

Geohash encoding

Geohash encodes coordinates by recursively bisecting the latitude/longitude bounding box and encoding 5 bits at a time into base-32 characters. Each additional character doubles the precision. At precision 8, the cell is approximately 38m × 19m. Adjacent cells share a common prefix, enabling efficient proximity queries.

Haversine distance

The Haversine formula computes great-circle distance on a sphere: a = sin²(Δlat/2) + cos(lat1)·cos(lat2)·sin²(Δlng/2); d = 2R·atan2(√a, √(1−a)). Using Earth's mean radius of 6,371.0088 km, this is accurate to within ~0.5% for any distance.

Frequently Asked Questions

DD (Decimal Degrees) is a single number like 40.7128. DMS (Degrees Minutes Seconds) breaks it into 40° 42' 46" N — the traditional navigation format. DDM (Degrees Decimal Minutes) is 40° 42.768' N, common in aviation and marine GPS. All three represent the same location. DD is preferred in web/software contexts. DMS is on paper maps and older GPS units. DDM is on ICAO aviation charts and marine chartplotters.

In Google Maps: right-click any point on the map and the coordinates appear at the top of the context menu in decimal degrees. On your phone: open Maps, tap and hold a location to drop a pin, then tap the pin — coordinates show at the bottom. On iPhone, the Compass app shows your current coordinates. For precise work, a dedicated GPS device or surveying app gives better accuracy than phone GPS.

The Haversine formula assumes Earth is a perfect sphere with a mean radius of 6,371 km. Earth is actually slightly flattened at the poles (an oblate spheroid), so Haversine has an error of up to about 0.5% for very long distances. For most applications — navigation, location-based searches, general GIS work — this is plenty accurate. For geodetic surveying that needs millimeter precision, use the Vincenty formula on the WGS84 ellipsoid.

Bearing is the direction you would travel from Point A to reach Point B, measured clockwise from true North. 0° = North, 90° = East, 180° = South, 270° = West. The tool also shows the compass direction abbreviation (N, NNE, NE, ENE, etc.) by dividing the circle into 16 equal sectors of 22.5°. This is the initial bearing — for long distances on a curved Earth, the bearing changes along the route.

No — this tool works with raw coordinates only. Address-to-coordinate conversion (geocoding) requires an external geocoding API such as Google Maps Geocoding API, OpenStreetMap Nominatim, or HERE Maps. These services look up an address string and return a lat/long pair. This tool takes lat/long as input and converts between coordinate formats — it does not query external APIs or perform address resolution.

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