Convert Latitude/Longitude to Decimal
Converting between DMS and decimal formats comes up constantly in mapping work.
This tool handles the conversion in both directions.
How to Use This Tool
Type your DMS coordinates into the form (include the hemisphere indicators), click convert, and copy the result.
One note: West and South show up as negative in decimal format, which trips people up sometimes if they’re not expecting it.
Example Conversions
| DMS Format | Decimal Degrees | Location |
|---|---|---|
| 34° 3′ 23″ N, 118° 14′ 37″ W | 34.0564, -118.2436 | Los Angeles, CA |
| 51° 30′ 26″ N, 0° 7′ 39″ W | 51.5072, -0.1275 | London, UK |
Frequently Asked Questions
1. What’s the difference between DMS and Decimal Degrees?
DMS divides degrees into minutes and seconds (base-60, courtesy of Babylonian astronomers). Decimal just expresses the same value as a regular number. Both are equally precise – it’s purely a formatting difference.
2. Why convert?
Your GIS software expects decimal, but half your sources use DMS. Converting by hand gets old fast, and it’s easy to fat-finger a calculation when you’re processing multiple coordinates.
3. The actual math?
Decimal Degrees = Degrees + (Minutes ÷ 60) + (Seconds ÷ 3600)
Then flip to negative for S and W. The tool handles both parts automatically.
4. What about going the other direction?
The tool converts both ways – DMS to decimal and decimal back to DMS.
Got questions or found a bug? Leave a comment.