Distance Between Two Places

What your result means

Distance

The great-circle distance over the Earth's surface: the shortest possible path, ignoring roads and terrain. Shown in statute miles, kilometers and nautical miles.

Bearing

The direction you would set off in, in degrees clockwise from true north and as a 16-point compass direction. "Back" is the bearing from the second place to the first.

Elevation and difference

Ground height at each point, from USGS 3DEP in the US and Terrain Tiles elsewhere, and how much higher one end is. The distance itself is measured at sea level; the height difference adds almost nothing to it (see limitations).

Average grade

The elevation difference divided by the distance, as a percent. Real routes climb and drop along the way, so use the elevation profile for a route's total climb.

Midpoint

The point halfway along the line. The link opens the halfway tool with nearby towns and places to meet.

How the distance is calculated: the haversine formula

With latitudes φ₁, φ₂ and longitudes λ₁, λ₂ in radians, and Earth's mean radius R = 6,371.0088 km (3,958.76 mi):

a = sin²(Δφ/2) + cos φ₁ · cos φ₂ · sin²(Δλ/2)
d = 2R · asin(√a)

The initial bearing θ, from north toward east:

θ = atan2(sin Δλ · cos φ₂, cos φ₁ · sin φ₂ − sin φ₁ · cos φ₂ · cos Δλ)

1. Each place comes from a search (OpenStreetMap Nominatim, then the US Census geocoder for US street addresses), your GPS, typed coordinates or a map click.
2. The distance, bearing and midpoint are calculated in your browser. Miles = km ÷ 1.609344; nautical miles = km ÷ 1.852.
3. Our server looks up the ground elevation at both points.
4. The page address keeps both points, so a shared link opens the same result.

Worked check, Denver to Salt Lake City: Δφ = 1.0216°, Δλ = -6.9063°, which gives d = 596.9 km = 370.9 mi, and θ = 283.2° (WNW).

Distance as the crow flies vs driving distance

The straight line is the shortest possible distance, so it is always the lower bound for any trip. Roads add distance in proportion to how indirect the network is: grids in flat cities add little, and mountains, coastlines, lakes and rivers add a lot. The straight line is the right number for flight planning, radio and signal range, delivery radii, "how far away is that storm" and comparing how close places are.

This tool doesn't give driving distance or driving time. We checked the free routing services before building it: the public OSRM demo server is for non-commercial use only, and the free plans of openrouteservice and GraphHopper also exclude commercial use. Because this site carries ads, it doesn't use them. The result links to Google Maps directions for the drive.

Accuracy and limitations

• Round Earth. Haversine assumes a sphere. On the WGS 84 ellipsoid, distances differ by up to about 0.5%; for a precise survey-grade figure, use a geodesic (Vincenty or Karney) calculator.
• Sea-level distance. The line is measured along the surface at sea level. Height barely changes it: at 5,276 ft, Denver is 0.025% farther from Earth's center, which adds that fraction to a distance.
• Where a city "is". A city search returns OpenStreetMap's point for it, usually downtown. Distances between city centers can differ by several miles from the distance between two specific addresses.
• Elevation of the ground. Elevations are bare-earth ground heights at the two points, not building floors or the height of a summit you did not click exactly.