Updated June 2026.
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Linear inches is the measurement airlines use to determine whether your checked bag is standard-size or oversized. It’s the total of your bag’s height plus width plus depth. If the number is 62 or under, you pay the standard checked bag fee. Over 62, you pay an oversized surcharge on top of that – usually $100-$200 extra each way.
The math is simple. The part most people get wrong is which dimensions to measure and whether to include wheels and handles. Here’s the full breakdown.
The Formula
Linear inches = Height + Width + Depth
Stand your suitcase upright. Measure height (top to bottom including wheels), width (left to right at widest), and depth (front to back at thickest). Add the three numbers together. That’s your linear inches.
Example: A bag measuring 28 x 20 x 14 inches = 28 + 20 + 14 = 62 linear inches. That’s right at the standard limit for most airlines.
Example: A bag measuring 30 x 21 x 15 inches = 30 + 21 + 15 = 66 linear inches. That’s 4 inches over the limit and would trigger an oversized fee.
What’s Included in the Measurement
Airlines measure the overall exterior dimensions. That means wheels, retractable handles (in the retracted position), external pockets, and any bulges from packing. Expansion zippers add 1-2 inches of depth when deployed, which can push a bag from 60 linear inches to 62-64.
Manufacturers often list “body only” dimensions that exclude wheels and handles. If you’re shopping for a checked bag and the listing says 28 x 20 x 13 (61 linear inches), the actual overall measurement with wheels and handle might be 30 x 20 x 14 (64 linear inches). That gap matters.
When in doubt, measure the bag yourself with a tape measure. Use the bag packed to your normal level, not empty. A stuffed soft-sided bag will measure larger than the same bag empty.
Linear Inch Limits by Airline
Most US airlines use the same standard: 62 linear inches maximum for standard checked bags.
Delta, United, American, Southwest, JetBlue, Alaska: 62 linear inches max. Bags over 62 inches incur oversized fees ($150-$200 each way on most carriers). Bags over 80 linear inches aren’t accepted at all on some airlines.
Spirit and Frontier: 62 linear inches for the first checked bag, with standard checked bag fees ($35-$70+ depending on booking channel). Oversized fees on top of the base fee.
International carriers vary more widely. Some European airlines measure in centimeters and set limits at 158cm total (which equals 62.2 linear inches). Asian carriers sometimes have different limits by fare class. Check your specific airline before you pack.
Common Checked Bag Sizes and Their Linear Inches
A 25-inch suitcase (medium checked) typically measures 25 x 17 x 11 inches overall = 53 linear inches. Well under the limit. This is the safe bet for checked bags.
A 28-inch suitcase (large checked) typically measures 28 x 20 x 14 inches overall = 62 linear inches. Right at the limit. Tight with wheels and handles included. Measure carefully before buying.
A 30-inch suitcase (extra-large) typically measures 30 x 21 x 15 inches overall = 66 linear inches. Over the limit. You’ll pay the oversized surcharge. For more on maximizing your checked bag space without going oversized, check our 62 linear inches guide.
How to Stay Under 62 Linear Inches
Buy a 27-28 inch checked bag and measure it with wheels before you pack. Most 28-inch bags from major brands (Samsonite, Travelpro, Delsey) are designed to hit exactly 62 linear inches, but measure yours specifically rather than trusting the listing.
Don’t use the expansion zipper unless you’ve confirmed the expanded dimensions stay under 62. Expanding adds 1-2 inches of depth, which can push a 61-inch bag to 63 inches.
Pack a soft-sided bag over hardside if you’re on the edge. Soft bags compress slightly, which can buy you an inch when the airline agent pushes on the bag. Hard cases don’t compress at all.
FAQ
What are linear inches for luggage?
Linear inches is the total of your bag’s height + width + depth, measured in inches. Airlines use this number to determine if a checked bag is standard-size (62 linear inches or under) or oversized (over 62). Example: 28 + 20 + 14 = 62 linear inches.
How do you calculate linear inches?
Measure your bag’s height (top to bottom with wheels), width (side to side), and depth (front to back). Add the three numbers. That’s your linear inches. Include wheels, handles, and any expansion.
What happens if my bag is over 62 linear inches?
You’ll pay an oversized bag surcharge on top of the standard checked bag fee. This ranges from $100-$200 each way depending on the airline. Bags over 80 linear inches may not be accepted at all on some carriers.
Is 62 linear inches the same on every airline?
Most US airlines use 62 linear inches as the standard limit. International carriers vary – some use 158cm (essentially the same at 62.2 inches) while others set different limits by fare class. Check your airline’s specific policy before you fly.