Latitude Longitude Converter
Two Notations, One Coordinate
The same point on Earth gets written two different ways depending on the source: GPS devices and web maps favor decimal degrees (40.7128°), while surveying, navigation charts, and older reference works favor degrees-minutes-seconds (40° 42' 46.08" N). Copying a coordinate from one system into a tool that expects the other is a common source of location errors. This calculator converts cleanly between them in both directions.
The Formula
Degrees = integer part of |DD|
Minutes = integer part of (|DD| − Degrees) × 60
Seconds = ((|DD| − Degrees) × 60 − Minutes) × 60
DMS → Decimal Degrees:
DD = Degrees + Minutes÷60 + Seconds÷3600
Worked Example
New York City's latitude, 40.7128°, converts to 40° 42' 46.08" N — and converting that same DMS value back reproduces exactly 40.7128°, confirming the round trip.
| Component | Value |
|---|---|
| Degrees | 40 |
| Minutes | 42 |
| Seconds | 46.08 |
Which Hemisphere Letter to Use
- Latitude — positive values are North (N), negative values are South (S).
- Longitude — positive values are East (E), negative values are West (W).
Where This Conversion Matters
- Transcribing coordinates from nautical or aviation charts — which traditionally use DMS notation — into GPS units or mapping software that expects decimal degrees.
- Cross-checking survey documents — legal land descriptions and older cartographic records often record positions in DMS.
- Avoiding sign and unit errors — a coordinate pasted in the wrong format can silently misplace a location by tens of miles.
How to Use This Calculator
- Choose a mode: "Decimal Degrees to DMS" or "DMS to Decimal Degrees".
- For DD to DMS: enter the decimal degree value and select whether it's a latitude or longitude.
- For DMS to DD: enter degrees, minutes, seconds, and the hemisphere letter (N, S, E, or W).
- Select Calculate to get the converted coordinate.
Related Calculations
Need a projected coordinate instead of latitude/longitude? See the UTM Coordinate Converter, or measure distance between two coordinate pairs with the Distance Between Coordinates Calculator.