Convert between true bearing and magnetic bearing using magnetic declination. This calculator helps with compass navigation, hiking, backpacking, map reading, route planning, bearing adjustment, and back bearing checks.
True to magnetic:
Enter a true map bearing and local magnetic declination to find the compass bearing to follow.
Magnetic to true:
Enter a compass bearing and declination to convert it back to a map or true north bearing.
Find bearing difference:
Enter a true bearing and magnetic bearing to estimate the declination difference between them.
A magnetic declination calculator helps adjust compass bearings so your map direction and compass direction match. This is useful for hiking, backpacking, hunting, field work, search routes, land navigation, and waypoint travel.
This calculator adjusts bearings using a declination value you enter. It does not look up live geomagnetic model data by location.
The common bearing adjustment formulas are:
Magnetic Bearing = True Bearing − Declination
True Bearing = Magnetic Bearing + Declination
Magnetic declination is the angle difference between true north and magnetic north at a specific location.
True bearing is based on geographic north. Magnetic bearing is based on magnetic north, which is what a magnetic compass points toward.
Use the formula magnetic bearing equals true bearing minus declination. If declination is west, enter it as a negative value when using signed declination.
Yes. Magnetic declination changes by location and also changes slowly over time, so it is best to use a current value for your route area.