Altitudes East and West

Hey IFC,

I have heard about flying at a even/odd altitude when travelling east and an even/odd altitude when flying west to avoid collisions. Can anyone help me in understanding which even/odd altitude travels east/west?

Thanks everyone!

When flying West, even if it’s Northwest or Southwest, your altitude at cruise should be even, 36,000, 38,000 etc…

When flying East, Northeast, Southeast you should be at and off altitude like 33,000 or 35,000


If you’re flying between heading 360° to 179° it’s gonna be an odd altitude.
Between heading 180° to 359° it’s an even altitude.


Here’s a diagram to help you out!


Adding onto what @CaptainSooraj said, its not based on heading but instead on magnetic course if I’m not mistaken, so be sure to keep note of that. And if you are flying in Chinese airspace you can stick another 100 feet onto your flight level if you want to keep it realistic.


This is a very broadly applicable rule, however, there VERY FEW exceptions. For example, some NAT tracks, especially those East bound, may include some even altitudes.

I would recommend to use an FPL planning software, like SimBrief, to get the exact altitudes in use at all time!

Yep! My bad. Magnetic course is what I meant.
And if you’re flying VFR, stick on a +500 feet to keep it realistic.

Refer to 6.6.7 of the ATC Manual and the Oceanic Flying section of the Flying Guide for possible answers to your question. Everything you need to know when it comes to flying in the Infinite Flight skies can be found within the User Guide as a whole. Enjoy! :)