Passenger load factor
Passenger load factor (PLF), also known as load factor (LF), is a fundamental efficiency metric in the airline industry that measures the percentage of an airline's available passenger seating capacity occupied by revenue-generating passengers over a given period.[1][2] It is calculated by dividing revenue passenger kilometers (RPK)—the total distance traveled by paying passengers—by available seat kilometers (ASK)—the total seating capacity multiplied by distance flown—and multiplying by 100 to express as a percentage; for a single flight, it simplifies to the ratio of passengers carried to total seats available.[3][4] PLF serves as a direct indicator of capacity utilization and revenue efficiency, with higher values signaling better financial performance by spreading fixed costs like fuel, crew, and aircraft depreciation across more passengers, thereby enhancing profitability amid volatile demand and operational expenses.[2][5] Airlines typically target PLF above 70-80% for viability, as levels below this threshold often result in losses due to underutilized assets, influencing strategic decisions on route planning, pricing, and fleet management.[6][4]Definition and Fundamentals
Core Definition
The passenger load factor (PLF), often simply termed load factor, quantifies the efficiency of passenger aircraft utilization in commercial aviation by expressing the ratio of revenue passengers carried to the total available seating capacity over a specified period, such as an individual flight, route, or entire airline network. This metric, expressed as a percentage, reflects how effectively an airline fills its seats with paying customers, excluding non-revenue passengers like crew or complimentary ticket holders.[1][7] Industry-standard computation derives PLF from aggregate traffic data: it divides revenue passenger-kilometers (RPK)—the product of revenue passengers and flight distance—by available seat-kilometers (ASK)—the product of total seats and flight distance—then multiplies by 100 to yield the percentage. For instance, if an airline operates five flights each covering 200 kilometers with 60 revenue passengers per flight and 100 seats available, the PLF is calculated as follows:This yields (60,000 passenger-kilometers / 100,000 seat-kilometers) = 60%, illustrating capacity utilization adjusted for distance.[1][4] For a single flight, the formula simplifies to (revenue passengers / available seats) × 100, omitting distance for point-to-point assessments, though the RPK/ASK method predominates for system-wide analysis due to its incorporation of varying route lengths and fleet mixes. PLF excludes cargo or ancillary loads, focusing solely on passenger seats, and serves as a foundational gauge of operational efficiency rather than direct profitability, which requires integration with yield and cost data.[7][8]