What is the most common carry-on size allowed by airlines worldwide?

55 × 40 × 23 cm (roughly 22 × 16 × 9 inches) is the most widely accepted size across European full-service carriers and many Asian airlines.

What carry-on size works on all airlines?

A bag of 55 × 35 × 25 cm or smaller fits the vast majority of airlines globally, including budget European carriers, US airlines, and Asian carriers.

Do US airlines use the same size limits as European airlines?

Broadly yes. The US standard of 22 × 14 × 9 inches (56 × 36 × 23 cm) is very close to the European full-service standard of 55 × 40 × 23 cm.

Which airlines have the smallest carry-on size limits?

Ryanair has the most restrictive size limit for free carry-on bags: 40 × 20 × 25 cm for standard fares. With a priority boarding ticket, the allowance rises to 55 × 40 × 20 cm.

Does the sizer check length, width, or depth most strictly?

Depth — the third dimension — is most often the enforced constraint. Bags that are slightly too thick fail the sizer even when length and width are within limits.

Carry-On Size Limits by Region: The Global Comparison Guide

Carry-on allowances are not globally standardised. A bag that passes effortlessly at a US airport may be refused at a European budget airline gate. Understanding the regional landscape saves you money and stress.

United States: The 22 × 14 × 9 Rule

US domestic airlines broadly follow a de facto standard of 22 × 14 × 9 inches (56 × 36 × 23 cm). This figure originates from FAA overhead bin advisory guidelines and has been adopted by American Airlines, Delta Air Lines, United Airlines, Alaska Airlines, and JetBlue. Southwest Airlines uses the same dimensions but does not enforce them with any rigour.

Key points for US travel:

The size limit includes wheels and handles
Enforcement is rare on domestic routes
Spirit Airlines and Frontier Airlines are stricter and charge separately for larger carry-on bags
Personal item limits (under-seat bag) are typically 18 × 14 × 8 inches

Europe: Two Very Different Worlds

European airlines split into two categories that have meaningfully different size allowances.

Budget Carriers (where size limits really matter)

Airline	Free Carry-On Size	Paid Cabin Bag
Ryanair	40 × 20 × 25 cm	55 × 40 × 20 cm
Wizz Air	40 × 30 × 20 cm	55 × 40 × 23 cm
easyJet	45 × 36 × 20 cm	56 × 45 × 25 cm
Vueling	40 × 20 × 30 cm	55 × 40 × 20 cm

Ryanair's free allowance is the most restrictive in Europe. Standard fare passengers may only bring a bag that fits under the seat — 40 × 20 × 25 cm. To use the overhead bin you must buy priority boarding or a cabin bag add-on.

Full-Service European Carriers

Airline	Carry-On Size
Lufthansa	55 × 40 × 23 cm
British Airways	56 × 45 × 25 cm
Air France	55 × 35 × 25 cm
KLM	55 × 35 × 25 cm
Swiss	55 × 40 × 23 cm
SAS	55 × 40 × 23 cm

The 55 × 40 × 23 cm standard is common across Star Alliance European members. British Airways is unusually generous at 56 × 45 × 25 cm.

Asia: Stricter Weight Limits, Similar Dimensions

Asian carriers typically publish similar dimensions to European airlines (56 × 36 × 23 cm is common) but enforce weight limits more strictly — typically 7 kg, compared to 8–12 kg on European full-service carriers.

Airline	Carry-On Size	Weight
Singapore Airlines	55 × 38 × 22 cm	7 kg
Japan Airlines	55 × 40 × 25 cm	10 kg
ANA	55 × 40 × 25 cm	10 kg
Thai Airways	56 × 45 × 25 cm	7 kg
AirAsia	56 × 36 × 23 cm	7 kg

Gulf Region: Generous Dimensions

Gulf carriers offer some of the most comfortable carry-on allowances globally.

Airline	Carry-On Size	Weight
Emirates	55 × 38 × 20 cm	7 kg
Qatar Airways	50 × 37 × 25 cm	7 kg
Etihad Airways	50 × 40 × 25 cm	7 kg

Despite generous size limits, Gulf carriers do weigh bags, and the 7 kg weight limit is enforced with more regularity than on European full-service airlines.

Latin America

Airline	Carry-On Size	Weight
LATAM	55 × 35 × 25 cm	8 kg
Avianca	55 × 35 × 25 cm	10 kg
Copa Airlines	55 × 35 × 25 cm	10 kg

LATAM and Avianca follow a consistent 55 × 35 × 25 cm standard across most of their networks.

Africa and Indian Ocean

African carriers generally follow the 56 × 36 × 23 cm standard with 7 kg weight limits. Kenya Airways and Ethiopian Airlines are the most consistent.

The "Universal" Carry-On Size

A bag of 55 × 35 × 25 cm (approximately 22 × 14 × 10 inches) fits every full-service airline globally and the paid cabin bag tiers on European budget airlines. It will not fit Ryanair's free under-seat allowance (40 × 20 × 25 cm), but no single bag can satisfy both Ryanair standard and full-service allowances simultaneously.

Which Dimension Gets Checked?

When airline staff use a physical bag sizer:

Depth (thickness) is the most commonly enforced dimension — the third number in any dimension set
Bags that are slightly too thick fail the sizer frame even when length and width appear fine
Soft-sided bags often compress enough to pass; rigid hard-shells either fit or they don't

If you are buying a bag specifically to pass airline sizers, prioritise depth. A bag 24–25 cm deep is safer than one at 26–28 cm, even if total volume is similar.