Work out seat revenue per kilometre instantly with clear inputs, formula shown and shareable results.
Yield is revenue divided by revenue passenger kilometres (passengers times distance), while RASK divides the same revenue by available seat kilometres (seats times distance). Yield measures pricing power; RASK folds in how full the aircraft was and is the figure that must beat CASK for the sector to make money.
Airline revenue metrics
Yield = revenue / (pax x km); RASK = revenue / (seats x km)
Fares do not rise linearly with distance, so revenue per kilometre falls on long sectors even though total fare is higher.
RASK against CASK. A rising yield with a falling load factor can still leave RASK below cost.