How we calculate our numbers

Every derived metric on this site is computed from the sourced core specification. Here is exactly how — so the numbers are checkable, and citable.

Our numbers

Every derived metric, formula by formula

Seats per metre

Formula: typical seats ÷ fuselage length

A density proxy you can compare across sizes. It is how the A380's double deck shows up in a single number — more seats per metre of fuselage than anything else flying.

Range per tonne

Formula: maximum range ÷ MTOW in tonnes

How far each tonne of maximum weight takes you. Smaller aircraft score dramatically higher — it is an honest way to see why the industry moved from quads to light twins.

Span-to-length ratio

Formula: wingspan ÷ fuselage length

A shape signature. Above 1.0 the wing is wider than the aircraft is long — rare, and the A380 is the only one here that does it.

Weight per metre

Formula: MTOW ÷ fuselage length

Range in hours

Formula: maximum range ÷ cruise speed

Weight per seat

Formula: MTOW ÷ typical seats

Caveats. Derived metrics use each family's flagship variant as specified in its table. Typical seating is the manufacturer's multi-class figure; real airline layouts vary. These are comparison tools, not operational data.

What the ✓ tick actually means

Operator fleet counts move constantly, and most aviation sites quietly present a stale number as fact. We do not. Every operator row on this site is one of two things, and we say which.

A row marked has been individually checked against a named, dated source — an airline filing, a manufacturer statement, or a maintained fleet record — and that source is listed at the bottom of the page. A row marked is an approximate snapshot: broadly right, good enough to reason about, and not something you should quote in a contract. Currently 7 of 264 operator rows carry a tick, and the flagship fleets — Emirates, Southwest, United — are among them. That number will only go up.

We would rather show you an honest ≈ than a confident lie.

Where the core data comes from

Core specifications are taken from manufacturer documents — Boeing and Airbus airport-planning manuals and technical pages — and type certificate data sheets, cited per row on every spec table. Operator fleet counts are approximate snapshots, marked with ≈ and a last-verified date, and re-checked against airline press material.

Where sources conflict, we say so on the page and cite both. If you spot an error, tell us — corrections are made visibly, not silently.