True vs Magnetic Heading
Last updated: April 20, 2026 · Maintained by Aviatr Editorial Team
What is True vs Magnetic Heading?
True heading is measured from geographic north; magnetic heading is measured from magnetic north, which the compass needle points toward. The angular difference between them is magnetic variation — a location-specific value that must be applied when converting between chart bearings drawn to true north and the compass headings flown by pilots.
How is True vs Magnetic Heading used?
Pilots encounter both references constantly. VFR and IFR chart courses are drawn from geographic north, so a plotted course of 090° true over central Germany requires subtraction of roughly 3° East variation to obtain the compass heading to fly. The mnemonic 'East is least, West is best' guides the calculation: variation East is subtracted from true to get magnetic; variation West is added. Airport runways are numbered by magnetic heading, so Runway 27 points 270° magnetic. As the Earth's magnetic field drifts over years, runway numbers are periodically updated — European airports have undergone several renumbering cycles in recent decades. IFR flight plans accept both true and magnetic track inputs; ATC systems convert automatically. Mixing the two references without applying variation is a known navigation error caught regularly during initial training.