Revenue Per Available Seat Mile - RASM

A unit of measurement that is used to compare the efficiency of various airlines. It is obtained by dividing operating income by available seat miles (ASM). Generally, the higher the RASM, the more profitable the airline in question. Revenue is represented in cents and is not solely limited to ticket sales.

Because it is more encompassing than total revenue - factoring in all operating revenue, in terms of capacity, rather than just passenger revenue - RASM has been adopted as a standard unit of measurement by most airlines. However, be aware that airlines, like many businesses, have traditionally favored metrics that cast them in the best possible light.