Refer to figure.
True Direction, the Geographic North Pole is taken as a geographic reference and is assigned an angular value of 000º T or 360°T.

In most light aircraft, It is not possible to measure true headings directly without the correct instruments. The primary source for directions inside a cockpit is the magnetic compass, which roughly aligns itself with the Magnetic North Pole and not with the True North Pole. The location of the Magnetic North Pole is not the same as the True/Geographic North Pole.

Magnetic Direction, refers to the Magnetic North Pole and is assigned an angular value of 000º M or 360º M.
Variation is the angular difference between the True and Magnetic North and is assigned in degrees East or West of the True North.

• If the Magnetic North is west of the True North, westerly variation, the magnetic direction will have a higher angular value than the true direction.
  • In this case, we add the variation to the True Heading to find the Magnetic Heading.
• If the Magnetic North is east of the True North, easterly variation, the magnetic direction will have a lower angular value than the true direction.
  • In this case, we subtract the variation from the True Heading to find the Magnetic Heading.

Variation West – Magnetic Best
Variation East – Magnetic Least