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Distance Calculator (Great-Circle, Haversine)

Great-circle distance from coordinates or US city presets, with flight and drive time estimates.

LIFESTYLE

Calculate the great-circle (as-the-crow-flies) distance between two points on Earth from latitude and longitude using the Haversine formula. Outputs miles, kilometers, nautical miles, initial bearing, and estimated flight and drive time. Pick from common US city presets or enter custom coordinates.

The Haversine formula treats Earth as a sphere with radius 6,371 km (3,959 mi), accurate within 0.5% for typical distances. Great-circle is the shortest path on a sphere - it appears curved on a Mercator map but is mathematically the most direct. Driving distance is typically 15-30% longer because roads follow terrain. Coordinates are decimal degrees: north and east positive, south and west negative. NYC (40.71, -74.01), LA (34.05, -118.24), Tokyo (35.68, 139.65).

Disclaimer: Haversine is accurate to ~0.5% on a sphere. Use Vincenty or WGS84 ellipsoid math for survey-grade work. Drive-time estimate assumes 60 mph average; actual time depends on traffic and route.

Distance Calculator (As-the-crow-flies)

Calculate the great-circle distance between two points on Earth from latitude and longitude using the Haversine formula. Outputs miles, kilometers, and nautical miles. Pick from common US city presets or enter custom coordinates.

Distance (miles)
2,445.6
Distance (km)3,935.7
Distance (nautical miles)2,125.1
Initial Bearing274° (W)
Estimated Flight Time (commercial)5h 23m
Estimated Drive Time~40h 46m
Straight-line distance assumes 60 mph average. Real driving distance is typically 15-30% longer.

How Great-Circle Distance Works

The Haversine formula calculates the shortest distance between two points on a sphere, given their latitude and longitude. It treats Earth as a sphere with mean radius 6,371 km (3,959 mi), which is accurate to within 0.5% for typical distances. For higher precision (geodesics on the actual oblate ellipsoid), the Vincenty formula is preferred but rarely necessary for everyday use.

Great-circle distance is "as the crow flies" - a straight line through the air. Driving distance is usually 15-30% longer because roads are not straight (highways follow terrain, cities have street grids). For an exact driving distance, use Google Maps or a routing API. The bearing shown here is the initial heading; great-circle routes curve on a Mercator map even though they are the shortest path on the globe.

Coordinates use decimal degrees. North latitude and east longitude are positive; south and west are negative. Examples: New York City (40.71, -74.01), Los Angeles (34.05, -118.24), Tokyo (35.68, 139.65), Sydney (-33.87, 151.21). One degree of latitude is always ~69 miles, while one degree of longitude varies from ~69 miles at the equator to 0 at the poles.

Haversine accurate within ~0.5% for short distances. For survey-grade precision or geodetic work, use Vincenty or the WGS84 ellipsoid.

Frequently Asked Questions

What is the difference between great-circle and driving distance?
Great-circle (also called "as the crow flies") is the shortest distance between two points on the surface of a sphere - what a plane would fly if there were no winds, no air-traffic-control routes, and no airspace restrictions. Driving distance follows roads, which are 15-30% longer than great-circle on average and can be 50%+ longer in mountainous terrain or where there is no direct highway between two cities.
How do I calculate distance between two cities by hand?
Use the Haversine formula: a = sin²(Δφ/2) + cos(φ₁)·cos(φ₂)·sin²(Δλ/2), then distance = 2R·atan2(√a, √(1-a)) where R = 3,959 mi (Earth radius). Δφ is the difference in latitudes in radians; Δλ is the difference in longitudes. For NYC (40.71°N, 74.01°W) to LA (34.05°N, 118.24°W): ~2,445 miles. Doing it by hand is tedious - this calculator does it instantly.
How long does a flight from New York to Los Angeles take?
Great-circle distance NYC → LA is about 2,445 miles. Commercial jets cruise at ~500 mph, so the air time is about 4.9 hours. Add 30 minutes for taxi, takeoff, and landing, and the total block time is roughly 5.5 hours. The eastbound return is actually faster (4.5-5 hours) because of jet-stream tailwinds.