Distance Between Coordinates Calculator (Haversine)

Slice a sphere through its centre and the cut's edge is a great circle; the shorter arc between two surface points along such a circle is provably the shortest surface path. That's why long-haul flights arc poleward on flat maps — the Mercator projection straightens rhumb lines, not geodesics, so the genuinely shortest route looks curved. Delhi to San Francisco passes near the Arctic; the 'straight' line on the map would be hundreds of km longer.

Against GPS receivers and Google Earth (which use the WGS-84 ellipsoid): within 0.3–0.5% — Earth's equatorial radius exceeds its polar by 21 km, and a single mean radius can't honor that. For logistics, aviation planning, store-locator radii and 'how far is it' questions, irrelevant; for property lines, cadastral work or anything legal, use ellipsoidal geodesics (Karney's GeographicLib is the modern standard) and the official local datum. The formula's other virtue is numerical: the older spherical-law-of-cosines version loses precision below ~1 km; haversine doesn't.

Decimal degrees: north latitude positive, south negative; east longitude positive, west negative. New York is (40.71, −74.01), Sydney (−33.87, 151.21). If your source gives degrees-minutes-seconds (40°42′46″N), convert with DD = D + M/60 + S/3600 — our DMS converter automates it. The classic error is a dropped minus sign, which silently relocates your point to the wrong hemisphere and produces a spectacular, plausible-looking wrong answer.

Different masters: the kilometre is SI; the statute mile is Roman legions via English law (5,280 ft); the nautical mile is geometry itself — one minute of latitude arc, 1,852 m by definition — which is why aviation and shipping never left it: charts are graduated in degrees, so distance and angle share a ruler. The bearing output here pairs naturally with NM: 'fly 245° for 612 NM' is a complete navigational sentence.