Time & Date · Travel & Distance
Great-circle Distance Calculator
Calculate the straight-line ('as the crow flies') distance between two cities or coordinates over the curved Earth, in kilometres, miles and nautical miles, with the initial compass bearing, the midpoint and an approximate flight time.
Also listed inUnit Converters
Your inputs
Quick start — try a typical case
Your result Live
Distance, New Delhi → London
6,724.04 km
4,178.13 miles · 3,630.69 nautical miles
- Approximate Flight Time
- 8 h 24 min 38 s
- Initial Bearing
- 315.6° (NW)
- Final Bearing
- 260.2° (W)
- Midpoint
- 46.8606° N, 46.2998° E
- On a Perfect Sphere (haversine)
- 6,711.26 km — -0.19 % different
How this is calculated
Vincenty's inverse formula on the WGS-84 ellipsoid; sphere check: d = 2R·asin√(sin²(Δφ/2) + cos φ₁ cos φ₂ sin²(Δλ/2))
- φ, λ
- Latitude and longitude
- R
- Mean Earth radius, 6,371.0088 km (for the haversine comparison)
The shortest path between two places on a globe is a 'great circle' — the reason flights from India to North America pass over the Arctic. Because the Earth is slightly flattened, the distance is computed on the WGS-84 ellipsoid used by GPS (accurate to millimetres); the simpler spherical formula is shown for comparison and differs by up to about 0.5 %.
Assumptions & sources
- City distances use approximate city-centre coordinates — use exact coordinates for airports or addresses.
- Distance is over the Earth's surface, ignoring altitude and terrain; road distances are longer.
- 1Direct and Inverse Solutions of Geodesics on the Ellipsoid (Vincenty, 1975) — Survey Review
- 2World Geodetic System 1984 (WGS 84) — U.S. National Geospatial-Intelligence Agency
Calculator ID GEO-GC-001 · version 1.0.0
Common questions
Why isn't the straight line on a map the shortest route?
Flat maps distort the globe. The shortest route is a great circle, which looks curved on most maps — that's why flights to the US from India fly north over Europe or the Arctic.
How accurate is this?
The ellipsoidal formula is accurate to well under a metre for the coordinates you give. City presets use city centres, so the distance between two airports can differ by a few kilometres.
How do I enter coordinates?
Choose 'Enter coordinates…' and type decimal degrees (28.6139, −74.006) or degrees-minutes-seconds like 28°36'50"N.