Definition
The specific altitudes that pilots operating under Visual Flight Rules (VFR) above 3,000 feet AGL must use when in level cruising flight, based on magnetic course. On a magnetic course of 0° through 179°, pilots fly odd thousands plus 500 feet (e.g., 3,500; 5,500; 7,500). On a magnetic course of 180° through 359°, pilots fly even thousands plus 500 feet (e.g., 4,500; 6,500; 8,500). The rule applies up to and including 18,000 feet MSL.
Plain English
When you're flying VFR more than 3,000 feet above the ground, the altitude you cruise at depends on which direction you're heading. Going roughly east, you fly at an odd-thousand altitude plus 500 feet. Going roughly west, you fly at an even-thousand altitude plus 500 feet. This keeps opposite-direction traffic separated by 1,000 feet.
Context Anchor
Seen in cross-country planning, navigation lessons, and any discussion of choosing an en route altitude for visual flight.
Derivation
VFR means visual flight rules: flying mainly by looking outside and staying clear of clouds. Cruising means the steady travel part of a flight after climb and before descent. Altitude comes from a word meaning height, which fits because this term is about the height you choose for that steady part of the flight.
Why Pilots Care
Ensures safe separation from other aircraft without relying on ATC for VFR traffic.
Analogy
Think of it like driving on a two-way road: eastbound traffic uses one lane, westbound uses the other. In the sky, the 'lanes' are stacked vertically by 1,000 feet, and your magnetic course tells you which one is yours.
Intuition Check
Do not read cruising altitude as simply a comfortable height for the trip. In this FAA use, it means a required standard altitude for the en route part of a VFR flight when the rule applies.
Example Sentence 1
Planning a cross-country with a magnetic course of 270°, the student selected 6,500 feet as the appropriate VFR cruising altitude.
Example Sentence 2
Westbound VFR flights typically use even altitudes plus 500 feet as their cruising altitudes.