Crow Flies Distance Calculator

Expert Verified by: David Chen, CFA • Senior Geographic Systems Analyst

Calculating the shortest path between two points on a sphere is essential for aviation, marine navigation, and logistics. This Crow Flies Distance Calculator uses the professional Haversine formula to provide highly accurate point-to-point distances across the globe.

Crow Flies Distance Calculator

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Crow Flies Distance Calculator Formula

The “As the Crow Flies” distance is calculated using the Haversine Formula:

a = sin²(Δφ/2) + cos φ1 ⋅ cos φ2 ⋅ sin²(Δλ/2)
c = 2 ⋅ atan2( √a, √(1−a) )
d = R ⋅ c

Source: Wikipedia – Haversine Formula | Movable Type Scripts

Variables:

• φ (Phi): Latitude of the point in radians.
• λ (Lambda): Longitude of the point in radians.
• Δφ / Δλ: The difference between latitudes and longitudes.
• R: Earth’s mean radius (approx. 6,371 km).
• d: The resulting great-circle distance.

What is Crow Flies Distance?

Crow flies distance, also known as the Great-Circle Distance, represents the shortest possible path between two points on the surface of a sphere. Unlike driving distance, which follows roads and turns, this calculation assumes a direct flight path.

This is the standard measurement used by pilots and GPS systems to determine the absolute geographic separation between coordinates, ignoring terrain or human-made infrastructure.

How to Calculate Crow Flies Distance (Example)

1. Identify your coordinates (e.g., London: 51.5, -0.12 and Paris: 48.8, 2.35).
2. Convert degrees to radians by multiplying by (π/180).
3. Apply the Haversine formula to find the central angle ($c$).
4. Multiply the angle by the Earth’s radius (6,371 km).
5. The result for London to Paris is approximately 344 km.

Related Calculators

• Flight Path Duration Estimator
• GPS Coordinate Converter
• Great Circle Route Mapper
• Metric to Imperial Distance Tool

Frequently Asked Questions (FAQ)

Is the Crow Flies distance the same as driving distance?
No. Driving distance is always longer because it follows roads, whereas Crow Flies is a straight-line geometric path.

How accurate is the Haversine formula?
It is accurate to within 0.5% for most applications. For extreme precision, Vincenty’s formulae are used to account for Earth’s ellipsoidal shape.

What is the Earth’s radius used in this calculator?
We use a mean radius of 6,371 kilometers (3,958.8 miles), which is the international standard.

Can I use negative numbers?
Yes. Southern latitudes and Western longitudes are represented as negative values in decimal degrees.