Few things are more frustrating at the start of a trip than being told at the gate that your cabin bag is too big or too heavy. It can mean an unexpected fee, a rushed repack in front of other passengers or a bag sent to the hold with your laptop still inside. The solution is simple: measure and weigh your bags at home, and know exactly what your ticket allows before you leave.
Why allowances vary so much
There is no single worldwide standard for cabin baggage. Each airline sets its own limits for size, weight and the number of bags, and those limits can change depending on the fare you booked, the route and your membership status. Two flights on the same day with different airlines may have very different rules.
That is why the most reliable source is the baggage information attached to your own booking, not a general list or what you remember from a previous trip.
Know the three numbers
For each bag you plan to bring on board, find these three details:
- Maximum dimensions: height, width and depth, usually including wheels and handles.
- Maximum weight: some airlines set a weight limit for cabin bags, while others only limit size.
- Number of items: whether you can bring a personal item, a larger cabin bag or both.
Write these down for each flight on your itinerary, including the return journey and any connections with other airlines.
How to measure a bag properly
Airlines usually measure the outside dimensions of a bag, including wheels, handles and any external pockets. Manufacturers sometimes list a size that does not include these parts, so measure your bag yourself.
- Stand the bag upright on a flat floor
- Measure height from the floor to the top of the handle when it is pushed down
- Measure width at the widest point, including side handles
- Measure depth with the bag packed, as soft bags expand when full
Measure again once the bag is packed. An expandable zip or bulging front pocket can push a soft bag over the limit.
How to weigh a bag at home
A small handheld luggage scale is the easiest way to weigh a bag. If you do not have one, use bathroom scales: weigh yourself, then weigh yourself holding the bag, and subtract the difference. Weigh the bag fully packed, with everything you plan to put in it on the day.
Aim to stay a little under the limit. It leaves room for a last-minute item and for anything you buy while you are away.
What to do if your bag is over the limit
- Wear the heaviest items: jackets, boots and jumpers.
- Move items to your personal item, if it has its own allowance.
- Swap to lighter versions: solid toiletries, a thinner book or an e-reader.
- Remove “just in case” items you are unlikely to use.
- Add a checked bag in advance if you really need more space, as it is often cheaper online than at the airport.
Soft bags versus hard cases
A hard-shell case keeps its shape, which makes it easy to know whether it will fit a sizer at the gate. Soft bags are often lighter and can squeeze into tight overhead lockers, but they can bulge when overfilled. Neither is better for everyone. If your airline has strict size checks, a bag that keeps its shape removes a lot of uncertainty.
Keep a record for future trips
Once you know the measurements and empty weight of your bags, write them down. Next time you book, you can compare them with the airline’s limits in seconds. Many travellers keep this information alongside their packing list. A web app such as PackChecklist.com can hold your trip list in the browser, so your notes and your packing plan stay in one place.
Takeaway: check your own booking for size, weight and number of bags, measure and weigh at home with the bag fully packed, and leave a small margin for the journey home.
