Use this calculator for flight-planning study or a first-pass cross-check when all inputs describe the same aircraft, atmospheric condition, and phase of flight.

True bearing (°)

Bearing measured from true north.

Variation (°)

Magnetic variation at the position; east positive, west negative.

Convert a true bearing to a magnetic bearing by subtracting east-positive variation. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Magnetic bearing (°)

Magnetic bearing normalized to zero through 360.

• Do not use a generic calculator in place of the current aircraft flight manual, approved performance data, operating limitations, NOTAMs, weather, or regulations. Real performance changes with configuration, runway condition, altitude, temperature, wind, loading, and technique.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check the result against the aircraft flight manual or approved planning system, then apply the required safety margins. Keep signed wind, heading, altitude, speed, and fuel conventions explicit.

• Magnetic Course Calculator

  Convert a true course to a magnetic course by subtracting the magnetic variation, east positive.

• True Bearing from Magnetic Calculator

  Convert a magnetic bearing to a true bearing by adding east-positive variation.

• Magnetic Heading Calculator

  Convert a true heading to a magnetic heading using east-positive variation (east is least).