What it means
Airlines sell seats on aircraft, and an empty seat earns nothing. To know how well they are filling those seats, they count the number of paying passengers and multiply by the distance each one travelled.
A single passenger who flies 500 miles produces 500 revenue passenger miles. The word revenue in the name matters.
Only passengers who pay a fare, or who redeem points that count as revenue under the airline's rules, are included. Staff flying free and some other non-revenue travellers are usually excluded, so the figure reflects actual commercial demand.
RPM is compared with available seat miles, which measure capacity. The comparison gives the load factor, the proportion of seat miles that were sold.
If load factor is falling while capacity is growing, the airline may be adding flights faster than customers are booking them. RPM also links to revenue through yield, which is the average revenue earned for each revenue passenger mile.
Dividing passenger revenue by RPM shows how much the airline collects for each mile of travel it sells, which is a useful check on pricing. Analysts watch yield alongside RPM because an airline can fill seats by cutting fares without improving its profit.
Airlines publish RPM figures each month or quarter, and investors use them to gauge demand trends and to compare carriers of different sizes. The figure is affected by the season, fuel prices, economic conditions and events such as strikes or disruptions.
Because routes vary in length, RPM gives a fairer picture of activity than simply counting passengers. The unit is also reported for the whole industry, which allows comparison of regions and carriers over time.
A sudden fall in industry RPM often points to a shock such as a recession or a travel restriction, while steady growth suggests rising demand for flying.
In practice
Real-world examples.
Example
A regional airline carries 40,000 passengers in a month on routes that average 400 miles. Its RPM for the month is 40,000 x 400 = 16,000,000, and it compares that with last year's figure to see whether demand is growing.
Example
An analyst reviews two airlines. One reports RPM growth of 8% on capacity growth of 3%, so its load factor is rising, while the other reports RPM growth of 2% on capacity growth of 6%, which suggests it is flying emptier planes.
Example
An airline's finance team notices that RPM is steady but passenger revenue has fallen 6%. They conclude that yield has dropped because fares were cut to fill seats, and they review the discounting policy. The team asks the pricing desk to report yield next to RPM in every monthly pack.
Formula
Calculation
RPM = Number of paying passengers x Miles flown
Load factor = RPM / Available seat miles
Suppose a flight has 180 seats and flies 1,200 miles with 150 paying passengers. RPM is 150 x 1,200 = 180,000. Available seat miles are 180 x 1,200 = 216,000, so the load factor is 180,000 / 216,000 = 0.8333, or about 83.3%. If the airline collected $27,000 in fares, yield is $27,000 / 180,000 = $0.15 per RPM.Case study
Seen in the real world.
Skyline Regional is an illustrative, fictional airline that added several new routes in a single year. Management was pleased because its passenger numbers rose by 20%.
The finance team looked at RPM and found it had grown only 9%, since most of the new passengers were on very short flights. Available seat miles had grown 15%, so load factor had slipped from 82% to 78% and yield had fallen as fares were cut to fill the new routes.
In this fictional case the airline trimmed the weakest routes and moved aircraft to longer, better-filled flights. The illustrative lesson is that counting passengers is not enough; RPM shows how much distance customers actually bought, which is what drives revenue. The airline now sets targets for RPM and yield together.
Watch out
Common mistakes.
- Counting passengers instead of passenger miles, which ignores the distance flown.
- Comparing RPM growth without looking at capacity growth, which hides changes in load factor.
- Ignoring yield, so that an airline appears successful when it is filling seats with heavily discounted fares.
Questions
People also ask.
What is the difference between RPM and ASM?
RPM measures the miles flown by paying passengers, while available seat miles measure the total miles of seats offered for sale.
How is load factor calculated?
Divide revenue passenger miles by available seat miles, and state the result as a percentage.
Are free tickets included in RPM?
Generally not, because RPM counts revenue passengers, although rules on loyalty-point travel vary by airline and reporting standard, so check the definition used in each report.
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