Measure length, width, and depth with a tape measure or ruler
The only way to know if your luggage fits airline rules or will fit in a car trunk is to measure it yourself. Airlines set size limits in inches or centimetres, and those limits are strict — a bag that is one inch over can be rejected at the gate, even if you have already paid for it.
Use a soft tape measure or a rigid ruler. Measure the outside of the bag, not the inside. Start at the furthest point on one side and stretch to the furthest point on the opposite side. Write down three numbers: length (the longest side), width (the middle side), and depth (the thinnest side when the bag is standing upright).
Measure with the bag empty and standing on a flat surface. Do not squeeze or compress it. If your bag has wheels, measure around them — the wheels are part of the bag's size. If it has a handle that folds down, measure with the handle in its normal carrying position, not folded away.
Key Takeaways
- Measure the outside of your bag in three directions: length, width, and depth, using a soft tape measure or ruler on a flat surface.
- Most airlines allow carry-on bags up to 22 by 14 by 9 inches, but some airlines and budget carriers have smaller limits, so check your airline's website before you travel.
- Checked baggage limits are usually 62 inches total (length plus width plus depth), but this varies by airline and ticket type.
- Write your measurements down and keep them with your travel documents so you know whether a bag will work for future trips.
Add up the three measurements for total bag size
Airlines often use a single number called the linear dimension or total dimension to describe checked luggage limits. This is the sum of length plus width plus depth. If an airline says checked bags must not exceed 62 inches, you add your three measurements together.
For example, if your suitcase is 28 inches long, 20 inches wide, and 12 inches deep, the total is 28 + 20 + 12 = 60 inches. That bag would be within the 62-inch limit. If it was 28 + 20 + 14 = 62 inches, it would be exactly at the limit and should be fine, but if it was 63 inches, it would be rejected.
Carry-on bags usually have separate limits for each dimension rather than a total. An airline might say carry-on bags must be no more than 22 inches long, 14 inches wide, and 9 inches deep. Your bag has to meet all three limits at once — it cannot be 23 inches long just because the width is small.
Check your airline's specific size rules before you pack
Size limits are not the same across all airlines. Major carriers like Delta, United, and American Airlines typically allow carry-on bags up to 22 by 14 by 9 inches, but budget airlines like Spirit and Frontier often allow only 21 by 13 by 8 inches. Some international carriers have different rules again.
The best place to find your airline's rules is the airline's own website. Search for "baggage policy" or "baggage dimensions" on their site. You will find a page that lists carry-on and checked bag limits, weight limits, and any fees for extra bags. Write down the numbers for your specific airline and ticket type — sometimes the limit changes depending on whether you bought a basic economy ticket or a higher class of service.
If you are flying with a bag you have never used before, measure it before you buy your ticket. If you already own the bag, measure it now and keep the measurements in a note on your phone or in your travel folder. That way you will know whether it works for your next trip without having to measure again.
Account for handles and wheels when measuring
Luggage handles and wheels add to the overall size of the bag, and airlines measure around them. If your rolling suitcase has a handle that extends upward, measure from the bottom of the bag to the top of the handle when the handle is in its normal upright position. If the handle retracts, measure with it extended, because that is how you will carry it through the airport.
Wheels are part of the bag's depth. Measure from the back of the bag to the front of the wheels. Do not try to subtract the wheel size or measure only the bag itself — the airline will measure the whole thing, wheels included.
Soft-sided bags with expandable sides are trickier. Measure them in their normal, non-expanded state. If the bag has a zipper that lets you expand it by a few inches, do not expand it before measuring. Measure the bag as it would normally sit in an overhead bin or under a seat.
Know the difference between carry-on and checked bag limits
Carry-on bags go in the overhead bin or under the seat in front of you. Checked bags go in the cargo hold. The size limits are different because the overhead bin is smaller than the cargo hold.
Carry-on limits are usually around 22 by 14 by 9 inches for major airlines, though this varies. Checked bag limits are usually around 62 inches total (length plus width plus depth), though some airlines allow up to 80 inches for oversized bags, which may cost extra.
If your bag is too large for carry-on but within checked limits, you will have to check it. If it is too large for both, you cannot bring it on the plane. Some airports have a physical size checker — a metal frame at the ticket counter — where you can test your bag before you check in, but the only reliable way to know is to measure it yourself first.
Measure soft-sided bags in their normal state
Soft-sided duffel bags and backpacks are harder to measure than hard-shell suitcases because they do not have a fixed shape. Measure them while they are sitting on a flat surface in the position you would normally pack them. Do not stuff them full and then measure — measure them empty or with a normal amount of clothing inside, the way you would actually travel with them.
If the bag has a zippered expansion panel, measure it without the panel expanded. Some bags can grow by 2 or 3 inches when you unzip the expansion, and airlines will not allow that extra size. Measure the bag in its smallest, normal configuration.
For backpacks, measure from the top of the pack to the bottom, from side to side, and from front to back. If the pack has a top pocket that sticks out, include that in your depth measurement. If it has side pockets, measure around them — they are part of the bag's overall width.
Record your measurements and keep them handy
Once you have measured your bag, write the three dimensions down somewhere you will not lose them. Take a photo of your bag with the measurements written on a piece of paper next to it, or store the numbers in a note on your phone labeled with the bag's name or color.
Keep these measurements with your travel documents or in a folder on your computer. The next time you book a flight, you can check your bag's measurements against the airline's limits without having to measure again. If you own multiple bags, measure all of them and keep a list so you know which one to use for each trip.
If you are buying a new bag and want to know whether it will work for your airline, check the product description on the retailer's website. Most luggage sellers list the dimensions in the product details. Measure those numbers against your airline's limits before you buy.
Frequently Asked Questions
Do I measure the bag with the handle up or down?
Measure with the handle in its normal carrying position. If the handle retracts or folds, measure with it extended, because that is how you will carry the bag through the airport and how the airline will see it.
What if my bag is exactly at the size limit?
If your measurements equal the airline's limit exactly, your bag should be within policy. However, if your measurements are even slightly over — by a quarter inch or more — the bag may be rejected. If you are very close to the limit, consider a smaller bag to be safe.
Can I compress my bag to make it smaller?
Compression bags and vacuum-seal bags can reduce the volume of clothing inside, but they do not change the outside dimensions of the luggage itself. Airlines measure the outside of the bag, not what is packed inside, so compression will not help you fit an oversized bag into the airline's limits.
Do wheels and handles count toward the size limit?
Yes. Wheels, handles, pockets, and any other part of the bag that sticks out are included in the measurement. Measure the bag in its full, normal state, including all attachments.
What if the airline's website does not list bag dimensions?
Call the airline's customer service line or use their online chat. They can tell you the exact carry-on and checked bag limits. Write down the numbers and keep them with your travel information for future reference.