Aviation
CASK (cost per available seat kilometre)
Total airline operating cost divided by ASKs.
Last reviewedWhat does CASK (cost per available seat kilometre) mean?
CASK is an airline's total operating cost divided by ASKs. Analysts also look at CASK excluding fuel (CASK ex-fuel), because fuel prices swing and are largely outside management's control. Example: a flight that costs 12,600 to operate and produces 180,000 ASKs has a CASK of 0.07. CASK falls with longer flights, larger and newer aircraft, more seats per aircraft and more hours flown per day, which is how low-cost carriers keep it low. Compare CASK only between airlines with similar route lengths.
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Related terms
- RASK (revenue per available seat kilometre)Total airline revenue divided by ASKs.
- Low-cost carrier (LCC)An airline built for the lowest cost per seat, selling cheap fares plus paid extras.
- Break-even load factorThe load factor at which revenue exactly covers costs at current fares.
- Unit economicsThe revenue and cost of one unit: one product, order or customer.
- ASK (available seat kilometre)One seat flown one kilometre: the standard measure of airline capacity.
- RPK (revenue passenger kilometre)One paying passenger flown one kilometre: the standard measure of airline traffic.
- Load factorThe share of seats filled with paying passengers: RPK divided by ASK.
- Yield (airlines)Passenger revenue per revenue passenger kilometre: the average fare per kilometre.