Magnetic Heading Calculator
Reviewed by Hamza Gujjar, Algorithm Architect & Software Developer
Last updated: July 27, 2026From map course to compass heading
Converting a true course (measured against geographic north on a chart) into a magnetic heading (what to actually fly on the compass) requires two corrections applied in sequence: wind correction angle, then magnetic variation.
Worked example
For a 90-degree true course, a 5-degree right wind correction, and 10 degrees east magnetic variation:
True Heading = 90 + 5 = 95 degrees
Magnetic Heading = 95 - 10 = 85.0 degrees magnetic
This follows the classic navigation mnemonic "east is least, west is best" - east variation is subtracted from true heading (making the magnetic number smaller), while west variation is added (making it larger), since variation describes the angular difference between true north and magnetic north at that location.