What is a Compass Bearing?
In navigation, a bearing is the horizontal angle between a reference direction (usually True North or Magnetic North) and a destination object. It is measured in degrees from 0° to 360° in a clockwise direction. Calculating the exact bearing between two coordinates allows pilots, sailors, and hikers to chart a direct line of travel.
Bearing vs. Heading: What is the Difference?
- Bearing: The absolute angle from your current location to your intended destination.
- Heading: The actual direction your vehicle (or body) is currently pointing. If crosswinds push an airplane off course, the pilot's heading will differ from the required bearing to reach the destination.
How to Calculate the Bearing Between Two Coordinates
Because the Earth is a sphere, you cannot use standard flat-plane geometry (like the Pythagorean theorem) to calculate accurate long-distance bearings. Instead, we use spherical trigonometry to calculate the initial bearing (forward azimuth).
The mathematical formula used by our calculator to find the angle (\theta) between Point 1 (φ1,λ1) and Point 2 (φ2,λ2) is:
Note: φ is latitude, λ is longitude, and Δλ is the difference in longitude. The result must be converted from radians back to degrees and normalized to a 0-360° compass rose.
Degrees to Cardinal Direction Conversion
While degrees provide pinpoint accuracy, human communication often relies on the 16-point compass rose. Our tool automatically converts the calculated mathematical degree into its corresponding cardinal or ordinal direction (e.g., North, North-Northeast, Southwest).
For quick reference, the primary cardinal points are mapped as follows:
Questions Fréquemment Posées
Cette boussole est-elle totalement gratuite ?
Oui, notre boussole numérique est 100 % gratuite et s'utilise directement dans votre navigateur.
Dois-je télécharger une application ?
Aucun téléchargement d'application n'est requis. Elle fonctionne directement dans Chrome, Safari et Edge.
Pourquoi ma boussole indique-t-elle la mauvaise direction ?
Les interférences magnétiques peuvent fausser les lectures. Déplacez votre appareil en formant un 8 pour le calibrer.