seatkilometers

Seatkilometers, or seat-kilometres, is a transportation metric that measures capacity by combining how many seats are available with how far they can travel. It is calculated by multiplying the number of seats by the distance covered, and is often used to describe potential or available capacity rather than actual passenger use. When a transportation service has multiple legs, seat-kilometres are summed across all legs.

In industry practice, seat-kilometres are commonly referred to as available seat-kilometres (ASK). This metric is contrasted with revenue passenger-kilometres (RPK), which tracks actual passenger traffic by multiplying the number of passengers by the distance traveled. The ratio of RPK to ASK is the load factor, a key indicator of how fully capacity is utilized.

Example: A single aircraft with 180 seats operating a nonstop route of 2,000 kilometers yields 360,000 seat-kilometres (180 × 2,000). If 120 passengers fly that route, the revenue passenger-kilometres would be 240,000 (120 × 2,000), and the load factor would be 240,000 / 360,000 = 0.667 (66.7%).

Seat-kilometres are useful for capacity planning, fleet and network analysis, and cost-per-kilometre calculations. However, as a measure of potential capacity, they do not reflect actual occupancy or revenue by themselves and are most informative when analyzed alongside PKM/RPK and related metrics.