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Lat/Long Converter

Converter

Point 1

Latitude

Longitude

Converted Formats

Decimal Degrees (DD)

40.7128, -74.0059

Degrees Minutes Seconds (DMS)

40° 42′ 46.0800″ N, 74° 0′ 21.2400″ W

Degrees Decimal Minutes (DDM)

40° 42.7680′ N, 74° 0.3540′ W

About This Tool

Latitude Longitude Converter – DD, DMS, and DDM Explained

Geographic coordinates are the universal language of location, but they come in three different dialects: Decimal Degrees (DD), Degrees Minutes Seconds (DMS), and Degrees Decimal Minutes (DDM). This converter lets you translate any coordinate between all three formats instantly and also calculates the straight-line (great-circle) distance between two locations using the Haversine formula.

What Are the Three Coordinate Formats?

Decimal Degrees (DD) is the most compact notation and the standard used by mapping APIs, databases, and web maps like Google Maps. Latitude and longitude are each expressed as a single decimal number: 40.7128, -74.0059. Positive latitude = North, negative latitude = South; positive longitude = East, negative = West.

Degrees Minutes Seconds (DMS) is the traditional cartographic format taught in geography classes and printed on paper topographic maps. The angular value is split into three parts: whole degrees, whole minutes (0–59), and seconds (0–59.9…). The hemisphere is indicated by a letter suffix: 40° 42′ 46.08″ N, 74° 0′ 21.24″ W. Many handheld GPS devices display coordinates in DMS by default.

Degrees Decimal Minutes (DDM) merges both approaches: whole degrees paired with decimal minutes, for example 40° 42.768′ N, 74° 0.354′ W. DDM is the preferred format in marine navigation (NMEA sentences from chart plotters output DDM) and in aviation waypoint databases, making it essential for sailors and pilots.

Conversion Formulas

All conversions route through Decimal Degrees as the internal representation. The key identities are:

  • DD → DMS: degrees = floor(|DD|); minutes = floor((|DD| − degrees) × 60); seconds = ((|DD| − degrees) × 60 − minutes) × 60. Apply the hemisphere sign last.
  • DMS → DD: DD = degrees + minutes/60 + seconds/3600. Negate for S or W.
  • DD → DDM: degrees = floor(|DD|); decimal minutes = (|DD| − degrees) × 60.
  • DDM → DD: DD = degrees + decimalMinutes/60. Negate for S or W.

Haversine Distance Formula

The Haversine formula computes the great-circle distance between two points on a sphere — the shortest path across the Earth's surface. Given two coordinate pairs (φ₁, λ₁) and (φ₂, λ₂) in radians:

  • a = sin²(Δφ/2) + cos φ₁ × cos φ₂ × sin²(Δλ/2)
  • c = 2 × atan2(√a, √(1 − a))
  • d = R × c, where R = 6 371 km (mean Earth radius)

Results are displayed simultaneously in kilometres, miles, and nautical miles (1 km = 0.621 371 mi = 0.539 957 NM). The formula assumes a perfect sphere; for distances under ~2 000 km, the error due to Earth's ellipsoidal shape is well under 0.5%.

Practical Applications

Web developers and GIS analysts receive coordinate data in a variety of formats depending on the data source — survey equipment typically outputs DMS, marine instruments use DDM, and REST APIs return DD. This converter eliminates manual calculation errors when moving data between systems.

Hikers and outdoor navigators often need to switch between the DD format shown on Google Maps and the DMS format on their GPS handheld. Enter the web map coordinate in DD and copy the DMS result directly into the device.

Mariners and aviators work primarily in DDM — chart plotters and flight-management computers accept waypoints in that format. Converting a DD coordinate from an online source to DDM takes one click here.

Researchers and educators can use the distance calculator to verify route lengths, compare expedition distances, or illustrate great-circle geometry in classroom settings.

Tips for Accurate Input

When entering DMS coordinates, ensure seconds are in the range 0–59.999 and minutes are 0–59. For DDM, decimal minutes must also be below 60. Latitude must lie between −90° and +90°, and longitude between −180° and +180°. The hemisphere selector (N/S for latitude, E/W for longitude) removes ambiguity; in DD mode the sign carries this information automatically.

Use the decimal places control to balance readability against precision. For general mapping, 4 decimal places in DD corresponds to about 11 metres of accuracy — more than sufficient for most use cases. Scientific surveys may need 7–8 decimal places.

Frequently Asked Questions

Is the Lat/Long Converter free?

Yes, Lat/Long Converter is totally free :)

Can I use the Lat/Long Converter offline?

Yes, you can install the webapp as PWA.

Is it safe to use Lat/Long Converter?

Yes, any data related to Lat/Long Converter only stored in your browser (if storage required). You can simply clear browser cache to clear all the stored data. We do not store any data on server.

How does the Latitude Longitude Converter work?

Enter your coordinate in Decimal Degrees (DD), Degrees Minutes Seconds (DMS), or Degrees Decimal Minutes (DDM), then choose the target format. The tool instantly converts the value using standard trigonometric formulas and displays the result in all three formats simultaneously for easy reference.

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

Decimal Degrees (DD) expresses coordinates as a single decimal number, e.g. 40.7128° — ideal for APIs and software. Degrees Minutes Seconds (DMS) breaks the value into whole degrees, whole minutes (0–59), and decimal seconds, e.g. 40° 42′ 46.08″ N — the traditional cartographic notation. Degrees Decimal Minutes (DDM) uses whole degrees and decimal minutes, e.g. 40° 42.768′ N — preferred in marine and aviation GPS devices.

How accurate is the coordinate conversion?

The conversions are mathematically exact to the precision of JavaScript's 64-bit floating-point arithmetic. You can control the number of displayed decimal places (0–8) without loss of underlying precision. For practical navigation purposes, 4 decimal places in DD (~11 m accuracy) and 2 decimal places in the seconds field of DMS are more than sufficient.

How is the distance between two points calculated?

The distance calculation uses the Haversine formula, which computes the great-circle distance across the surface of a sphere. It assumes a mean Earth radius of 6 371 km. The result is displayed simultaneously in kilometres, miles, and nautical miles. For very long distances (thousands of kilometres) the error from Earth's ellipsoidal shape is under 0.5%.

Why do negative DD values appear without a letter?

In Decimal Degrees notation, the hemisphere is encoded in the sign: positive latitude is North, negative is South; positive longitude is East, negative is West. When the tool converts to DMS or DDM, it replaces the sign with the explicit hemisphere letter (N, S, E, or W) so both notations represent the same point unambiguously.

Can I use this tool for Google Maps or OpenStreetMap links?

Yes. The tool generates direct links to Google Maps and OpenStreetMap for any coordinate pair you enter. Both services accept Decimal Degrees in their URLs, so the converter always outputs the DD value needed regardless of the format you entered.