Check carry-on size against airline rules.
Cabin bag rules are checked dimension by dimension against a sizer frame, not on total volume, so a bag can be under the linear total and still be rejected for being a few centimetres too deep. This checker sorts both your bag and the allowance from largest to smallest before comparing, which means orientation does not matter — exactly how a sizer works. The tightest dimension is what decides the outcome, and depth is almost always the one that fails, because it is the dimension that expands when you overpack and the one that external pockets and wheels quietly add to.
Dimension comparison
Sort bag and allowance largest to smallest, then compare each pair
Verdict
Fits if every sorted bag dimension is within the matching allowance dimension
Because a sizer frame does not care which side you call length. A 55 x 22 x 38 cm bag and a 55 x 38 x 22 cm bag are the same object and will fit or fail identically. Sorting both sets largest to smallest reproduces exactly what happens when the bag is dropped into the frame.
Yes. Published limits are external dimensions including wheels, handles, feet and side pockets. This is the most common reason a bag advertised as cabin-sized fails a sizer — the case body fits, but the wheels add 3 to 5 cm to the depth.