Quick Facts
- Type
- Financial Metric
- Also Known As
- CASM
- Used By
- Airlines, Analysts
Definition#
CASM (Cost per Available Seat Mile) is calculated by dividing total operating costs by the total number of available seat miles produced. It is the fundamental measure of airline unit cost.
Why It Matters Operationally#
Lower CASM indicates greater cost efficiency. Low-cost carriers target CASM reductions through high seat density, quick turnarounds, and single fleet types. CASM varies significantly by carrier model, stage length, and labor costs.