Bearing Calculator
Find the initial compass bearing from one GPS coordinate to another — the heading you'd start out on to follow the shortest path between two points.
Inputs
- Point 1 Latitude
- Point 1 Longitude
- Point 2 Latitude
- Point 2 Longitude
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Saved Scenarios
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Initial Bearing (°)
148.1
Spark says
Formula
- \varphi, \lambda
- — Latitude and longitude in radians
What is the Bearing Calculator?
Initial bearing is the compass direction you'd start heading in to travel along the great-circle path from one point to another — note that on a long journey, the bearing actually needed to follow that great circle changes continuously, so this is only the starting heading.
Use this when plotting a flight or sailing route's initial heading, orienting a directional antenna or solar panel toward a specific location, or working out roughly which direction one place lies from another for navigation or curiosity.
How to use it
- 1 Enter the starting point's latitude and longitude.
- 2 Enter the destination point's latitude and longitude.
Understanding Bearing Calculator
Bearing calculations sit at the intersection of two ideas that feel like they should be simple but aren't: 'north' isn't as fixed a reference as it seems, and the shortest path between two points on a sphere doesn't behave like a straight line does on a flat map.
On the first point, this calculator returns true bearing — the heading measured relative to true geographic north (the direction to Earth's rotational axis), not magnetic bearing, which is measured relative to magnetic north (the direction a compass needle points, toward Earth's magnetic north pole). The two differ by an amount called magnetic declination, which varies by location — it can be anywhere from roughly 0° to over 20° depending on where on Earth you are — and it also drifts slowly over years as Earth's magnetic field shifts. Anyone using this calculator's output with an actual magnetic compass needs to apply their local declination correction; pilots and mariners do this routinely, since aviation and marine charts are built around this exact distinction.
The second, more conceptually surprising point is why 'initial bearing' is even a meaningful phrase rather than just 'bearing.' On a flat map, the shortest path between two points is a straight line with one constant direction. On a sphere, it isn't — the shortest path (a great-circle route) requires continuously changing your heading as you travel, except in the special cases of traveling along the equator or due north-south along a meridian. This is precisely why long-haul flight paths, when plotted on a standard flat map projection, appear to curve dramatically toward the poles rather than tracing a straight line between departure and arrival cities — the curved-looking path is actually the shorter one, and the 'straight line' on the flat map would be the longer route in real-world distance.
The formula this calculator uses (derived from spherical trigonometry, based on each point's latitude and the difference in longitude between them) computes exactly this initial heading — the direction you'd point a compass at the very start of the journey to begin following the shortest great-circle path. For most everyday uses (roughly orienting toward a location, planning a short trip, aligning equipment), this initial bearing is close enough to constant that the distinction from a full great-circle path doesn't matter much. For genuine long-distance navigation, it's the starting point of a heading that a pilot, ship's navigator, or navigation system will continuously recalculate along the route.
Worked examples
Advantages
- •Uses the true great-circle bearing rather than a flat-map approximation, matching how aircraft and ships actually navigate.
- •Works for any two points on Earth, regardless of distance.
- •Pairs naturally with the distance and midpoint calculators for full route planning.
- •Gives an exact numeric heading rather than a vague compass-direction guess.
Limitations
- •This is the initial bearing only, not a constant heading — following a single fixed compass bearing traces a different path (a rhumb line) than the shortest great-circle route, except along the equator or a meridian.
- •Doesn't account for magnetic declination — this is true (geographic) bearing, not magnetic compass bearing, which differs by location and changes slowly over time.
Common mistakes
- ⚠️ Assuming the initial bearing stays constant for the whole journey — on a great-circle route, the true heading changes continuously except along the equator or a meridian.
- ⚠️ Confusing true bearing with magnetic bearing — a magnetic compass reads relative to magnetic north, which differs from true north by an amount (declination) that varies by location.
- ⚠️ Expecting a straight line on a flat map to match the calculated bearing — map projections distort direction, especially at higher latitudes, which is why great-circle routes look curved on a flat map.
Tips
- 💡 If working with a magnetic compass, look up the local magnetic declination and adjust this true bearing accordingly before navigating.
- 💡 For long routes, remember the bearing needs to be recalculated periodically along a great-circle path — this calculator gives only the starting heading.
- 💡 Pair this with the GPS distance calculator to get both the direction and the length of a route in one pass.
- 💡 Bearings near due north (close to 0° or 360°) can look dramatically different with tiny coordinate changes — double-check inputs if the result seems unexpected.
Real-life uses
- Plotting the initial heading for a flight or sailing route
- Orienting a directional antenna, satellite dish, or solar panel toward a target location
- Estimating which direction one city or landmark lies relative to another
- Cross-checking a navigation app's stated heading for a route
Frequently asked questions
Why does bearing change during a long flight?
Great-circle routes (the shortest path on a sphere) require a continuously changing heading, except when traveling along the equator or due north/south — this is why long-haul flight paths curve on a flat map.
Is this true bearing or magnetic bearing?
This is true bearing, measured relative to geographic north. Magnetic compass bearing differs by an amount called declination that varies by location and changes slowly over time — adjust accordingly if using a physical compass.
Why does a great-circle route look curved on a flat map?
Flat map projections distort distance and direction, especially near the poles — the curved-looking path is actually the shortest real-world route, while a straight line on the flat map would be longer in reality.
Does the bearing stay the same if I reverse the two points?
No — the return bearing (from point 2 back to point 1) generally isn't simply the original bearing plus 180°, except in special cases, because of the same great-circle geometry that makes bearing change along a route.
How accurate is this for short distances, like across a city?
Very accurate — over short distances, Earth's curvature has minimal effect, so the calculated bearing closely matches what you'd measure on a local flat map or compass (after accounting for magnetic declination).
Sources & references
calixo.cloud/geo-map/bearing-calculator/ — free calculator, no signup required.