Measure length, width, and height with a tape measure or ruler
To measure your luggage, you need the three dimensions: length, width, and height. Use a soft measuring tape (the kind tailors use) or a rigid ruler. Soft tape works best because it conforms to the shape of your bag, especially if your luggage is rounded or has wheels.
Place your bag on a flat surface and measure from the furthest point on one side to the furthest point on the opposite side. Do this for all three directions. Write down each number in inches or centimeters — whichever your airline uses. Most U.S. airlines list dimensions in inches; European airlines often use centimeters.
Measure the bag itself, not the contents. If your luggage has wheels, measure from the bottom of the wheels to the top of the bag. If it has a handle, measure from the bottom to the top of the handle when it is fully extended. Airlines measure the entire footprint of the bag as it sits.
Key Takeaways
- Measure length, width, and height using a soft tape measure, recording the furthest points on each side of your bag.
- Include wheels and extended handles in your measurements because airlines measure the entire bag as it would sit in a bin or hold.
- Add the three dimensions together to find your bag's total linear inches (or centimeters), which many airlines use to determine carry-on and checked bag limits.
- Check your specific airline's size rules before you travel, because limits vary — a bag that fits on one airline may not fit on another.
- Measure your bag before packing it, since a stuffed bag may be slightly larger than an empty one.
Calculate total linear inches if your airline uses that measurement
Some airlines don't list individual dimension limits. Instead, they use linear inches (or linear centimeters), which is the sum of all three measurements added together. To calculate it, add length + width + height. For example, a bag that is 22 inches long, 14 inches wide, and 9 inches tall would be 22 + 14 + 9 = 45 linear inches.
Most carry-on bags fall between 40 and 50 linear inches. Most checked bags fall between 62 and 80 linear inches, depending on the airline. Check your airline's website for their specific limit — it is usually listed under "baggage" or "checked baggage" in their policies.
Understand 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. These have stricter size limits because space is limited. Most U.S. airlines allow carry-on bags up to 22 × 14 × 9 inches, though some budget airlines are smaller. Checked bags go in the cargo hold and have more generous limits — typically up to 62 × 26 × 11 inches or 62 linear inches total.
Your airline's website lists both limits clearly. If your bag is close to the limit, measure it twice to be sure. A bag that is even one inch over can be rejected at the gate, and you may have to pay a fee or check it instead.
Measure your bag before you pack it
An empty bag is easier to measure accurately than a full one. Measure your luggage in its normal resting position — not compressed or stretched. If your bag has a soft shell, it may expand slightly when packed, so if you are close to the limit, measure it again after packing to be safe.
If your bag is borderline and you are unsure, contact your airline directly. Some airlines have staff at the airport who can verify size before you check in, and it is better to know ahead of time than to arrive at the gate and find out your bag is too large.
Use a luggage scale to check weight at the same time
While you are measuring, also weigh your bag. Most airlines have weight limits for checked bags — typically 50 pounds for domestic flights and 70 pounds for international flights. A digital luggage scale costs $10 to $20 and hangs from your bag so you can weigh it before you leave home.
Weigh your bag fully packed, the way it will be when you check it. If it is over the limit, remove items or redistribute weight across multiple bags. Going over the weight limit usually costs $75 to $200 per bag, depending on the airline.
Check your specific airline's rules before you travel
Luggage limits vary widely. Budget airlines like Spirit and Frontier have smaller carry-on allowances than full-service carriers. International airlines may have different rules than domestic ones. Some airlines charge for carry-on bags; others include two checked bags free.
Visit your airline's website and search for "baggage policy" or "baggage allowance." Write down the carry-on and checked bag dimensions and weight limits for your specific flight. If you are flying with a connecting flight on a different airline, check both airlines' rules — you must meet the strictest limit.
Frequently Asked Questions
Do I measure the bag with or without wheels?
Measure with the wheels attached. Airlines measure the entire bag as it sits, including wheels and any protruding handles. The wheels are part of the bag's footprint.
What if my bag is slightly over the size limit?
Contact your airline before you travel. Some airlines have a small grace margin and may allow bags that are an inch or two over. Others are strict. It is better to know ahead of time than to be turned away at the gate.
Can I compress my bag to make it smaller?
Compression bags can reduce volume, but they do not change the bag's outer dimensions. If your bag is too large, compression will not help. If you are close to the limit, compression may help slightly, but measure after compression to be sure.
Do I need to measure my bag every time I travel?
No. Once you know your bag's dimensions, you can note them down and refer to them. Measure again only if you buy a new bag or if you are unsure whether an old bag still fits your airline's current rules.
What is the difference between linear inches and regular inches?
Linear inches is the sum of all three dimensions added together. Regular inches refers to each individual measurement. Airlines use linear inches as a shorthand way to set a single size limit instead of listing three separate limits.