§ 1 · On measuring

Measure it the way the airport will.

A cabin limit is the opening of a frame at the gate, and the frame reads the bag in the state it arrives — on its wheels, packed, with every pocket zipped over its contents. Three habits shrink the distance between a tape at home and a frame at the airport.

1.Stand it upright. The frame meets a standing bag, so the first number is the one you get with the wheels on the floor. A bag lying flat shows its length, and on a spinner that is not the number the gate reads.

2.Pack it first. An empty shell and a loaded one are different objects. Fill the bag the way it will travel, then measure — fabric panels give under a zip, and every millimetre of give changes the standing figure.

3.Count the extras. Wheel housings add to the base, a folded handle rides along the spine, and a stuffed front pocket widens the bag. The limit covers the whole object, so the tape has to as well.

The three numbers, read in order.

Charts write a limit as height × width × depth, with the standing side first. The order matters on a roll-aboard: the same bag quoted as 55 × 40 × 20 is 55 centimetres tall only until a deeper wheel housing arrives on the next model.

When two airlines publish different frames, the smaller one decides the trip. A connecting ticket simply runs the bag past two sizers, one leg after another, and the stricter of the two sets the bar.

The whole object counts. A bag sold as “56 cm” whose casters bring the standing height to 59 will be measured at 59 — the frame does not subtract the parts it finds inconvenient.
— a measuring note

Leather suitcases stacked before packing — Fig. 1 — The number on the shelf describes the shell. The number at the gate describes the packed bag.

Size is one gate. Weight is the other.

Some operators publish a cabin weight cap and some publish none at all. Caps normally sit between 5 and 10 kilograms, yet the outliers run both ways:

Emirates7 kg
AirAsia7 kg
Korean Air10 kg
KLM12 kg
easyJet15 kg

Where an airline prints nothing, the gate usually asks for nothing — although some crews do spot-weigh cabin bags at boarding, so a quick look at the scale column before check-in costs nothing either. Every weight shown here comes from the carrier’s own published rules.

The personal item — the second bag.

Most fares also carry a small personal item beside the cabin bag: a backpack, a laptop sleeve or a handbag that slides under the seat in front. Its limit is separate and usually runs near 40 × 30 × 15 centimetres, though the exact figure differs from operator to operator.

Under-seat space is tighter than the overhead bin, and on a full flight it is the second place the gate looks. A bag that will not slide under cleanly starts counting against the main allowance instead.

Fabric bags forgive a squeezed sizer; rigid ones do not. When a frame is borderline, a soft-sided bag clears more often than a hard case, millimetre for millimetre.
— soft shell versus hard shell

Compare your packed bag against the table: find the airline flying your leg, read its frame, and match the standing height, width and depth of the bag you actually packed.

Turn to the table