🌐 Latitude & Longitude Tools
DMS ↔ decimal · haversine distanceHow to use the latitude & longitude tools
Two useful helpers for maps, GPS data and geography homework:
- Convert DMS ↔ decimal. Coordinates are often written as degrees, minutes and seconds (e.g. 39°54′26″N). Type the three parts and get the decimal form (39.9072) — or paste a decimal coordinate and read its DMS form. Negative values mean south (latitude) or west (longitude).
- Distance between two points. Enter any two latitude/longitude pairs and the tool computes the great-circle distance using the haversine formula — the same method used by mapping libraries — in kilometers and miles.
Formulas used
Decimal = degrees + minutes/60 + seconds/3600. Haversine: a = sin²(Δφ/2) + cos φ1 · cos φ2 · sin²(Δλ/2); d = 2R · asin(√a) with Earth radius R = 6371 km.
FAQ
Why does my DMS to decimal result look different from a map app? Map apps often use the WGS84 datum variants, or rounded seconds. Differences of a few meters are normal and acceptable for navigation; surveying requires a geodetic library.
How to use — 30 seconds
Type a decimal latitude/longitude — or a DMS pair like 51°30′26″N — to convert both ways. Use the distance tab to measure the great-circle distance between two coordinates (haversine formula).