Bearing Calculator (Azimuth & Direction)
Compute and convert navigation bearings: azimuth <→ quadrant bearing, and bearing between two points from coordinates. Ideal for surveying, mapping, and field navigation.
1. Azimuth to Bearing
2. Bearing to Azimuth
Start & End Coordinates
Use any consistent planar coordinate system (e.g., local grid, UTM easting/northing, or simple X/Y in meters or feet).
Results
ΔE = —, ΔN = —
Compass Visualization
The compass below shows the current azimuth/bearing direction. It updates when you run any conversion.
Current azimuth: —
Current bearing: —
What is a bearing?
In navigation, surveying, and engineering, a bearing is the direction from one point to another, expressed as an angle measured clockwise from a reference direction, usually north. Bearings are used to describe lines on maps, set out property boundaries, steer ships and aircraft, and align engineering works.
Azimuth vs. quadrant bearing
There are two common ways to express a bearing:
- Azimuth: a single angle from 0° to 360°, measured clockwise from north. Example: 135°.
- Quadrant bearing (also called compass bearing): an angle within a quadrant, measured away from north or south toward east or west. Example: N 45° E or S 20° W.
Quadrant bearing format
Written as: [N or S] θ° [E or W],
where 0° ≤ θ ≤ 90°.
Examples:
- N 30° E → 30° east of north
- S 10° W → 10° west of south
Conversion formulas
1. Azimuth → quadrant bearing
Let Az be the azimuth in degrees, normalized to
0° ≤ Az < 360°.
If 0° ≤ Az ≤ 90°:
Bearing = N Az E
If 90° < Az ≤ 180°:
Bearing angle = 180° − Az
Bearing = S (180° − Az) E
If 180° < Az ≤ 270°:
Bearing angle = Az − 180°
Bearing = S (Az − 180°) W
If 270° < Az < 360°:
Bearing angle = 360° − Az
Bearing = N (360° − Az) W
2. Quadrant bearing → azimuth
Let θ be the quadrant angle (0°–90°).
- N θ E → Az = θ
- S θ E → Az = 180° − θ
- S θ W → Az = 180° + θ
- N θ W → Az = 360° − θ
Bearing between two points (planar approximation)
For local engineering and surveying work, coordinates are often treated as planar (e.g., in meters or feet). Suppose you have:
- Start point: (x₁, y₁)
- End point: (x₂, y₂)
Assume x is east (Easting) and y is north (Northing).
Step 1: Compute deltas
ΔE = x₂ − x₁
ΔN = y₂ − y₁
Step 2: Azimuth using atan2
Az (radians) = atan2(ΔE, ΔN)
Az (degrees) = Az (radians) × 180/π
Normalize to 0°–360°:
if Az < 0 then Az = Az + 360°
Once you have the azimuth, you can convert it to a quadrant bearing using the rules above.
Worked example
Start point (x₁, y₁) = (1000, 2000)
End point (x₂, y₂) =
(1200, 2300)
- ΔE = 1200 − 1000 = 200
- ΔN = 2300 − 2000 = 300
- Az = atan2(200, 300) ≈ 33.69°
- Since 0°–90°, bearing = N 33.69° E
True, magnetic, and grid bearings
The calculator works in pure geometry. In practice, you may encounter:
- True bearing: measured from true (geographic) north.
- Magnetic bearing: measured from magnetic north (affected by declination).
- Grid bearing: measured from the north of a map projection grid (e.g., UTM grid north).
To convert between them you must apply local declination and convergence corrections, which depend on your location and map projection.
Common pitfalls
- Mixing up ΔE and ΔN: atan2 must use (ΔE, ΔN) in that order if azimuth is from north.
- Forgetting to normalize angles: always bring results into 0°–360° or −180°–+180° as required.
- Using planar formulas over large distances: for long lines on the Earth’s surface, use geodetic formulas (e.g., Vincenty) instead of simple ΔE/ΔN.