Add the three sides, then compare to the limit
Linear inches is simply the sum of a bag's length, width and height. Airlines use it as one number to check whether luggage fits their size rule. Measure the full exterior — wheels, feet and the retracted handle all count.
The two limits that matter
Carry-on caps out around 45 inches so the bag fits an overhead bin; checked bags get 62 before oversize fees start. The gap between them is where most bags land.
Under 45 inches rides in the cabin; up to 62 must be checked; over 62 usually means an oversize charge.
Common limits and the mistakes that blow past them
| Airline | Carry-on | Checked |
|---|---|---|
| American, Delta, United, JetBlue | 45 in (22×14×9) | 62 in |
| Southwest | 50 in (24×16×10) | 62 in |
| Frontier, Spirit | 40 in (18×14×8) | up to 80 in |
| Lufthansa | 50 in (22×18×10) | 62 in |
- Forgetting the wheels. They add 1–2 inches of height and airlines do count them.
- Handle left up. Measure with the telescoping handle collapsed, not extended.
- Weight is separate. Passing the size rule does not help if you are over the 50 lb (23 kg) weight cap.
Common questions
Do wheels and handles count in linear inches?
Yes. Airlines measure the total exterior of the bag, so wheels, the telescoping handle and any bulging pockets are all included. Measure with the handle pushed down and use the widest point of each side.
Is 62 linear inches the same on every airline?
Most major carriers use 62 inches (158 cm) for checked bags. Some budget airlines allow up to 80 inches for an extra fee, and carry-on limits vary from about 40 to 50. Always check your own airline.
Are linear inches the same as the dimensions?
No. Dimensions are the three separate measurements; linear inches is their sum. A 30 by 20 by 12 inch bag has those dimensions but 62 linear inches.
