Aviation Training Experts

Aviation Training Experts™

Magnetic Variation Calculator

Convert true course or heading to magnetic, or magnetic to true, using east or west variation. This free aviation calculator helps pilots with navigation, chart work, and heading conversions.

Calculate Magnetic Variation Conversion

Enter a direction, variation, and conversion type to calculate the corrected aviation heading or course.

True / Magnetic Conversion

How It Works

True to Magnetic:
East is least, West is best
Magnetic to True:
Reverse the process
Rules:
True to Magnetic: subtract East, add West
Magnetic to True: add East, subtract West

This calculator applies the standard aviation variation rules and normalizes the result to a heading between 000° and 360°.

What Is Magnetic Variation?

Magnetic variation is the angular difference between true north and magnetic north at a specific location. Because navigation charts and winds are often referenced to true north, while aircraft compasses reference magnetic north, pilots need variation to convert directions correctly.

Variation changes by location, which is why charts and navigation sources show local east or west variation values.

Why Pilots Use a Magnetic Variation Calculator

Magnetic Variation FAQ

What does “east is least, west is best” mean?

It is a memory aid for converting true to magnetic. Subtract east variation and add west variation.

Is variation the same as deviation?

No. Variation is the difference between true north and magnetic north. Deviation is compass error caused by magnetic influences in the aircraft.

Do I use local variation from the chart?

Yes. Use the variation shown for the area or route you are flying, based on current chart or navigation data.

Why is this important in aviation?

Correctly converting between true and magnetic values helps pilots maintain accurate navigation, heading selection, and flight planning.