The Only Carry-on Packing Checklist You Need

Carry-on-only travel is not about being minimalist for the sake of it. It is about not standing at a baggage carousel in Barcelona for 45 minutes after an overnight flight when you could already be at your hotel.

Real airline size rules

Ignore the standard "56x36x23 cm" that gets quoted online. Real published limits vary more than that, and low-cost carriers enforce them:

• Ryanair: free small bag 40x25x20 cm. Anything larger requires Priority Boarding (paid), which allows 55x40x20 cm.
• Wizz Air: 40x30x20 cm free. Larger carry-on is a paid add-on.
• easyJet: 45x36x20 cm underseat free; larger requires Up Front or Extra Legroom seats.
• British Airways, Lufthansa, KLM: 56x45x25 cm plus a personal item.
• Delta, United, American: 22x14x9 inches (56x35x23 cm) plus a personal item.
• Emirates, Qatar, Singapore: 55x38x20 cm, plus a personal item, with weight limits of 7-10 kg depending on carrier.

Weight is where U.S. and non-U.S. carriers differ most. U.S. domestic carriers do not usually weigh carry-ons. Most European and Asian carriers do, and the limit is often 8 kg total - which a hardcase alone can eat 3-4 kg of.

What actually fits in 40 liters

A well-packed 40L carry-on, with packing cubes, can hold about a week's worth of clothing for most people:

• 5 T-shirts or shirts, rolled.
• 2 pairs of trousers or 1 pair of trousers plus 1 skirt/dress.
• 1 light jacket or fleece.
• 7 pairs of underwear and socks.
• 1 pair of dress shoes (worn) plus one packed lighter pair.
• Toiletries in a 1L clear bag.
• Laptop, cables, adapter, book.

The core checklist

Personal item (goes under the seat)

• Passport and printed backup itinerary.
• Phone, charger, power bank (100Wh max in cabin).
• Wallet with two payment methods.
• Noise-cancelling headphones or earplugs.
• Refillable empty water bottle.
• Snack for the flight (dry snacks are fine at security, most fresh fruit is fine domestically but not internationally).
• Any medication you cannot go a day without.

Carry-on (overhead)

• 3-4 days of clothing in packing cubes.
• Toiletries: solid bar shampoo saves space and does not count as a liquid.
• Underwear and socks (packed dense).
• Compact rain layer.
• Universal power adapter.
• A spare set of underwear and one T-shirt in your personal item in case the carry-on is gate-checked and delayed.

Liquids, gels, batteries

The 100 ml / 3.4 oz rule still applies at most airports. The upgrade to next-generation CT scanners is rolling out through 2025-2026 at airports including LHR, JFK T4, LAX TBIT and SIN Changi, and passengers there can leave liquids and laptops in the bag. Do not assume - check the airport's site before you arrive.

Batteries have their own rules and no airline waives them:

• Spare lithium batteries and power banks: cabin only, never in checked luggage.
• Under 100 Wh: allowed without permission.
• 100-160 Wh: allowed with airline approval, usually maximum 2 per passenger.
• Over 160 Wh: not permitted on passenger aircraft.

Tips from frequent flyers

Wear your bulkiest layer through security. A ski jacket around your waist saves 4 liters of packing space and does not count against any allowance.

• Choose fabrics that dry overnight - merino wool T-shirts, synthetic trousers. You can wash and re-wear.
• Pack toiletries in a hanging bag. Hotel bathroom counters are always too small.
• Leave 10-15% of the bag empty for anything you buy on the trip.
• If your airline is strict, weigh the bag at home before you leave. Small digital luggage scales weigh 100 g and cost under $10.