DMS to Decimal Degrees Converter

Nautical charts, surveying paperwork and some GPS receivers state coordinates in degrees, minutes and seconds (DMS). Most modern mapping tools — Google Maps, GPX files, GIS software — need decimal degrees instead. This tool does that conversion.

Formula: decimal degrees = degrees + minutes/60 + seconds/3600.

Worked example

45° 30′ 15″: 30/60 = 0.5, and 15/3600 = 0.004167. 45 + 0.5 + 0.004167 = 45.504167°.

Where this comes up

• Typing a coordinate from a chart, deed or survey document into Google Maps or a GPS app
• Converting old map or aviation waypoint data into a modern lat/long format
• Astronomy calculations that need a decimal angle rather than DMS notation