Sizer

How we work it out

Every figure on this page is computed from the data behind the site. If the data changes, this page changes with it.

Which number we use

An airline measures the outside of your bag — wheels and handle included. That is the only figure that matters at a gate, and it is not always the one you find online. Some manufacturers publish both and say which is which; Travelpro states outright that you should compare the overall number against your airline's limit. Others publish one figure without saying. Marketplace listings are worst: the same bag carries different dimensions across sellers.

So we rank sources, and we only recommend a bag on one we can stand behind.

SourceRecommend on it?Bags
We measured it ourselvesYes0
The manufacturer's own overall figure — wheels and handle includedYes38
A review publication measured itNo — shown and attributed11
One figure, without saying whichNo9
Explicitly the packing sizeNo0
A marketplace or retail listingPossiobly, if it is the manufacturers site.0

38 of 58 bags on this site currently meet that bar. The rest are shown with their source named while we replace them at the manufacturer.

Five answers, not two

Yes or no is the wrong shape for this question, because airlines differ in how hard they check. A bag a centimetre over is a non-event at one airline and a fee at another.

Fits
Inside the limit with room to spare.
Tight
Legal, but with no margin — and the airline measures.
Probably fine
Over the limit, but barely — at an airline someone has checked on, and which tolerates far more than this. Only offered where we have read how staff actually behave, never on an assumed score.
Risky
Over the limit, at an airline that often doesn't check.
Over
Over the limit at an airline that does check.

How strictly an airline checks

A score from 1 to 10, and it means one thing only: how likely the published limit is to be enforced. It is not how restrictive the rules are — the rules are already the box we compare against, and counting them twice would make a small allowance look worse than it is.

The score decides how far over the limit is still worth showing you as a risk rather than a refusal:

ScoreWhat it meansOverage still shown as a risk
1–3Effectively never measuredup to 5 cm
4–5Occasional, usually when the bins are fillingup to 3 cm
6–7Frames at the gate; staff use judgementup to 1.5 cm
8–10Measured as routine — over is overnone

Where we have not researched an airline's enforcement, we assume it is strict. Being over-cautious costs you some convenience; the other direction costs you a gate fee.

The rules beyond length × width × depth

Soft bags give, hard shells don't

A soft-sided bag squashes into a gate sizer in a way a polycarbonate shell never will. We allow 2 cm off the shortest side of a soft bag, and nothing off a hard one. It is a modest allowance on purpose — enough to stop us calling a duffel a failure over a centimetre, not enough to pretend a bag is smaller than it is.

Sum-of-sides limits

11 of the 83 airlines here publish a linear limit — length plus width plus depth — as well as, or instead of, three separate maximums. A bag can pass all three individual limits and fail the total, so we check both and report whichever it fails.

Personal items are a separate box

66 airlines publish an under-seat size as well as an overhead one, and the two are not related. We check a bag against the box for the job you say it is doing, and we never substitute a generic "personal item size" for an airline that has not published one — an invented box produces confident wrong answers, which is worse than saying we do not know.

Weight, where it is published

64 airlines cap the weight of a cabin bag. We can only compare that against the bag's empty weight, because what you pack is yours to know — so we flag when the bag alone uses up a large share of the allowance, and leave the rest to you.

The fare, not just the airline

Cabin allowance is a property of the ticket. The same airline on the same aircraft grants a different bag on a basic fare than on a flexible one, and five of the airlines here grant no cabin bag at all on their cheapest. Unless you tell us the fare, we answer for the cheapest economy ticket that airline sells — the least generous honest assumption.

What we don't know

  • Nothing is measured by us. We rely on the manufacturer's published overall figure. If they are wrong, so are we — which is why we say where every number came from.
  • 9 of 83 airlines are left out of the fraction because their cheapest fare includes no cabin bag at any size. Aeroméxico, Avianca, easyJet, Frontier, GOL Linhas Aéreas, LATAM Airlines, Ryanair, Vueling, Wizz Air sell you a seat and a bag separately. Counting them as failures would blame the bag for a fare, so a coverage figure here reads "of 74" rather than "of 83".
  • We have read all 83 airlines' published cabin limits. There is no airline on this site whose limit we are guessing at. Where one is added and not yet read, it is excluded from every count rather than assumed — an unread airline must never render as a lenient one.
  • Some airlines contradict themselves. United publishes a carry-on limit in both inches and centimetres, and the two disagree — a 35.5 cm bag passes one and fails the other. Where that happens we use the stricter figure on each dimension.
  • Nothing resolves below 0.3 cm. Not a tape measure, not a soft-sided bag, not a gate sizer. A difference smaller than that is reported as "at the line", not as a pass or a failure.

Every source we used, and whether we actually read it →