In my experience: 1. "Altitude" is primarily related to height based on distance from ground or sea-level. This is not related to land formations, etc. but rather one's general location in the air. 2. "Elevation" is similar, but most often based on the height of grounded objects or land formations. In summary: Altitude= height in air (airplane, mountain, etc.) Elevation= height in air, grounded objects/land formations (mountain, etc.) Source: self (American English)