Carry-On Bag Size: Dimensions, Capacity and Which Bags Fit
For anyone buying or packing a cabin bag: the dimensions a carry-on has to meet, what the 18-, 20-, 21- and 22-inch labels really mean, and how much fits inside each size.
The standard carry-on bag size in the US is 22 × 14 × 9 inches (56 × 36 × 23 cm), measured including wheels and handles, or 45 linear inches. Most international airlines allow about 55 × 40 × 23 cm (21.5 × 15.5 × 9 in) or slightly less, often with a 7–10 kg weight limit. A bag of 21.5 × 14 × 9 in fits both.
- US standard
- 22 × 14 × 9 in
- In cm
- 56 × 36 × 23 cm
- International
- 55 × 40 × 23 cm
- Typical capacity
- 35–42 liters
On this page
Standard carry-on bag dimensions
Every airline sets its own limit, but they cluster around three sizes. A bag that meets both of the first two is accepted by nearly every full-service airline; a bag built to the third is accepted only by Southwest and Frontier.
| Limit | Inches | Centimeters | Linear total | Box volume | Used by |
|---|---|---|---|---|---|
| US standard | 22 × 14 × 9 | 56 × 36 × 23 | 45 in / 114 cm | 45 L | American, Delta, United, Alaska, JetBlue |
| International full-service | 21.5 × 15.5 × 9 | 55 × 40 × 23 | 46 in / 118 cm | 51 L | Air Canada, Lufthansa, Turkish Airlines; others at 55 × 35 to 40 × 20 to 25 cm |
| US large | 24 × 16 × 10 | 61 × 41 × 25 | 50 in / 127 cm | 63 L | Southwest, Frontier (paid add-on on most Frontier fares) |
The international column is wider (15.5 in vs 14 in) but shorter (21.5 in vs 22 in). That is why a bag sized 21.5 × 14 × 9 in (55 × 36 × 23 cm) is the one size that meets both the US standard and the common international limit. Many brands sell exactly this size as an "international carry-on". Some airlines set a lower 20 cm depth limit, so a bag that is also no deeper than 8 in (20 cm) when packed is the most broadly compliant shape.
Airline-by-airline limits, weight caps and the rules for basic fares are on the carry-on rules by airline page.
18, 20, 21 and 22-inch carry-ons compared
The size in the product name is the height, but brands disagree on whether it includes wheels. The overall dimensions below are typical of each label; check the listing of the bag you are buying.
| Label | Typical overall size (in) | cm | Packable capacity | Fits |
|---|---|---|---|---|
| 16–18 in underseater | 16–18 × 13 × 8–9 | 41–46 × 33 × 20–23 | 20–28 L | Under the seat on many airlines; personal item only where the bag is within that airline's personal-item size |
| 19–20 in | 20 × 14 × 8–9 | 51 × 36 × 20–23 | 30–36 L | All US and most international carry-on limits |
| 21 in "international" | 21.5 × 14–15.5 × 9 | 55 × 36–40 × 23 | 33–40 L | Both the 22 × 14 × 9 in and 55 × 40 × 23 cm limits, if no wider than 14 in |
| 22 in | 22 × 14 × 9 | 56 × 36 × 23 | 35–42 L | US standard exactly; usually 1 cm too tall for 55 cm limits |
| 22 in body + wheels | 23–24 × 14–15 × 9–10 | 58–61 × 36–38 × 23–25 | 42–48 L | Southwest and Frontier only; fails the 22-inch limit |
An expansion zipper usually adds 1.5 to 2 in (4 to 5 cm) of depth, taking a 9-inch bag to 10.5 or 11 in. That passes at Southwest but not in a 22 × 14 × 9 in sizer. Keep the expansion closed for the flight, or use it only on the trip home if you will check the bag.
How much fits in a carry-on
A 22 × 14 × 9 in box holds 45.4 liters. A wheeled suitcase of those outer dimensions packs about 35 to 42 liters, because the wheels, handle tubes and shell take the rest. A soft carry-on backpack or duffel of the same outer size packs closer to the full 40 to 45 liters.
- 3 to 5 nights of warm-weather clothes fit loosely, with shoes and a toiletry bag.
- About a week fits with compression packing cubes, one extra pair of shoes and clothes you can rewear.
- Liquids are limited by security, not by the bag: containers of 3.4 oz (100 mL) or less, in one quart-size (about 1 liter) bag per passenger, at US and most other airports.
Weight is the second limit outside the US. A polycarbonate carry-on weighing 7 lb (3.2 kg) empty leaves only 8.4 lb (3.8 kg) for contents on an airline with a 7 kg cap. On those routes a lighter soft bag, at 4–5 lb (1.8–2.3 kg), buys you more packing weight than a larger shell.
Types of carry-on bag
| Type | Typical empty weight | Size behavior | Best for |
|---|---|---|---|
| Hard-shell spinner | 6–8 lb (2.7–3.6 kg) | Fixed outer size; four wheels add height | Smooth airports, fragile items |
| Soft-sided two-wheel | 5–8 lb (2.3–3.6 kg) | In-line wheels are recessed and take less height | Maximum packable space within 22 in |
| Travel backpack (35–45 L) | 2.5–4.5 lb (1.1–2 kg) | Bulges when overfilled; compression straps help | Stairs, cobblestones, weight-capped airlines |
| Duffel (35–45 L) | 1.5–3.5 lb (0.7–1.6 kg) | Squeezes into sizers; no rigid frame | Short trips, car travel |
| Bi-fold garment bag | 3–6 lb (1.4–2.7 kg) | Folds to about 22 × 14 × 4–8 in | Suits and dresses |
For backpack dimensions see backpack sizes by type; for soft bags in liters, the duffel bag guide; and for travelling with a suit, garment bag sizes.
Personal item vs carry-on
Most fares include a carry-on for the overhead bin plus one smaller personal item for under the seat in front of you. The personal item is the bag that has to be small: limits run from 17 × 10 × 9 in (United) to 18 × 14 × 8 in (American), and in Europe 40 × 30 × 20 cm (15.7 × 11.8 × 7.9 in) on Ryanair and Wizz Air.
| Carry-on | Personal item | |
|---|---|---|
| Typical US limit | 22 × 14 × 9 in (56 × 36 × 23 cm) | 17–18 × 10–14 × 8–9 in |
| Capacity | 35–45 L | 15–30 L |
| Goes | Overhead bin | Under the seat in front |
| Typical bags | Wheeled suitcase, travel backpack, duffel | Small backpack, laptop bag, tote, purse, camera bag |
| Included on basic fares | Not on United basic economy (most routes) or ultra-low-cost fares | Yes, on almost every airline |
Measuring a bag for the airline sizer
- Pack the bag first. Soft bags and front pockets grow by an inch or more when full.
- Measure height from the floor to the top of the highest handle, with the trolley handle down and wheels on the floor.
- Measure width and depth at the widest points, including side handles, wheel housings and any item strapped to the outside.
- Compare each dimension separately. For carry-on limits a bag must pass all three; a short, wide bag does not get credit for being short.
- Leave a margin of about half an inch (1 cm) if you fly low-cost airlines that use rigid sizers, since a bag that fits exactly can still jam at the wheels.
On many newer narrow-body aircraft, enlarged bins take 22 × 14 × 9 in bags on their side, wheels first, rather than flat. A bag that is exactly within the limit slides in; one that is half an inch too wide often does not, even if the gate agent let it through.
For the full range of suitcase sizes, including checked luggage, see the luggage size chart.
Frequently asked questions
Is a 22-inch suitcase a carry-on?
Yes in the US, if the 22 inches includes the wheels. A case listed as 22 in body height usually measures 23 to 24 in with spinner wheels and fails the 22 × 14 × 9 in limit. Check the overall height in the listing, not the name.
Is a 20-inch bag a carry-on?
Yes. A 20-inch suitcase (usually 20–21.5 in tall overall) fits every major US airline and most international full-service carriers. It is the safest size if you fly several airlines, but it holds about 5 liters less than a 22-inch case.
What is the carry-on size in cm?
22 × 14 × 9 inches is 55.9 × 35.6 × 22.9 cm, which airlines round to 56 × 36 × 23 cm (Delta lists 56 × 35 × 23 cm). The common European and Asian size is 55 × 40 × 20 or 55 × 40 × 23 cm.
Can a backpack be a carry-on?
Yes. A backpack within 22 × 14 × 9 in counts as a carry-on, and a smaller one (about 17 × 13 × 8 in or less) usually counts as a personal item. Travel backpacks of 35 to 45 liters are built to the carry-on limit.
Do airlines measure carry-on bags?
Gate agents check bags that look large, usually by asking you to place them in a sizer frame at the gate. Low-cost airlines check most systematically. If the bag does not fit, it is checked at the gate, often with a fee.
How many linear inches is a carry-on?
45 linear inches (114 cm) for the 22 × 14 × 9 in standard. Delta states both the individual dimensions and the 45-inch total. Southwest's and Frontier's 24 × 16 × 10 in limit is 50 linear inches.