Measuring
How to read the cabin box an airline gives you
Airlines print three numbers and almost never say what they include. They include everything. Wheels, feet, the handle housing, the little rubber bumper on the corner. If it sticks out, it counts.
That is why the number on the label of a case is the wrong one to compare. A case sold as a twenty inch is twenty inches of shell, measured up the front, and the wheels underneath it add somewhere between an inch and two. We publish both figures on every page. The label size sits in the specs, and the measured outside sits in the table below it, down to the tenth of an inch. Of the 139 cases and bags we make, 100 have a full measured outside box on their page.
The boxes worth knowing
| Box | Inches | Ours that clear it | What it is |
|---|---|---|---|
| US majors | 22 x 14 x 9 | 36 of 100 | The overhead allowance printed by most large US carriers. |
| Roomier domestic | 24 x 16 x 10 | 69 of 100 | A handful of US carriers publish a larger cabin box than the rest. |
| International standard | 21.5 x 15.5 x 9 | 34 of 100 | The IATA guideline a lot of overseas carriers copy word for word. |
| Personal item | 18 x 14 x 8 | 18 of 100 | The bag that goes under the seat in front of you. |
| Tight personal item | 17 x 13 x 8 | 15 of 100 | The smallest under-seat box in common use. |
Measuring at home
Stand the case upright on a hard floor, the way it rolls. Run the tape from the floor to the top of the retracted handle, not to the top of the shell. That is the first number. The second is the width at the widest point of the shell, which on a spinner is usually across the middle rather than at the corners. The third is depth, front to back, with the expansion zip closed and nothing in the front pocket.
- Measure with the case empty. A packed soft-side grows in the depth, sometimes by an inch.
- Round up, never down. Gate staff round up too.
- If the case expands, the expanded depth is the one that matters at the gate.
- A dented corner or a bulging front pocket reads as extra depth in a sizer frame.
What a sizer frame actually tests
The metal frame at the gate does not measure anything. It is a pass or fail. The case either drops in and comes out again, or it does not. Which means the order of your three numbers does not matter, only the set of them. A case that is twenty two by fourteen by nine goes into a frame the same way whichever face you present, so long as every side is under the matching side of the frame. Our checker works on the same rule. It sorts your three numbers, sorts the case, and compares them in order.
Try it with the box off your own airline page rather than the one we assumed. Carriers change these numbers and the difference between 22 x 14 x 9 and 21.5 x 15.5 x 9 is enough to move 2 of our shells from one column to the other.
