A complete suite of free online geo calculators — convert GPS coordinates between Decimal Degrees (DD), Degrees-Decimal-Minutes (DDM), Degrees-Minutes-Seconds (DMS), and UTM; compute forward and reverse bearings with Vincenty-accurate geodesic distance; find geographic midpoints; offset a destination by bearing and distance; build a bounding box from a center point and radius (with GeoJSON bbox output); convert distance and area units; and solve speed, time, travel time, and ETA problems. All math runs locally in your browser on the WGS84 ellipsoid — GPS-grade accuracy, no signup, no data leaves your device.
Pick a calculator from the sidebar — eight tools grouped by Coordinates, Navigation, Unit Converters, and Travel.
Type values directly into any input — every result updates live, no Convert button needed.
Coordinate fields accept decimal degrees (e.g. 37.5665, 126.9780) unless a DMS / DDM / UTM tab is selected.
Click the copy icon on any result row to copy the formatted value to your clipboard.
Use the solve-for tabs inside each tool (e.g. Speed / Time / Distance) to change which field is the unknown.
Switch output units freely — distances in km / m / mi / ft / nm, areas in km² / m² / mi² / ac / ha.
Coordinate converter: DD ↔ DDM ↔ DMS ↔ UTM with all formats shown at once
Bearing & distance calculator: forward bearing, reverse bearing, cardinal direction, Vincenty geodesic distance
Geographic midpoint between two lat/lon points using great-circle interpolation
Coordinate offset / destination point solver (origin + bearing + distance → new lat/lon)
Bounding box from center + radius with ready-to-use GeoJSON bbox (west, south, east, north)
Distance unit converter: km, m, mi, ft, yd, nm, cm, mm
Area unit converter: km², m², mi², acres, hectares, ft², yd²
Speed / Distance / Time solver with ETA and travel-time breakdown (h, min, s)
WGS84 geodesic math — GPS-accurate at any scale, anywhere on Earth
100 % client-side — works offline, nothing is uploaded or logged