Checked baggage fees have long mystified American travelers, who believe that the base fare they hear is the bulk of what they'll pay to check a bag. In reality, the final price before reaching the counter involves a fee structure of tiers for both weight and size, not all of which apply to all bags.
In this guide
Weight Comes First
Then Come the Dimensions - in Their Own Way
When Both Applies, the Higher Fee Comes First
Here’s what you need to know to figure out what you're getting into before your next flight: weight limits such as a bag even a hair over 50 pounds can mean a punishing jump to the next fee tier, while linear dimensions can quickly escalate when you measure the max weight and size before the counter. How do checked bag fee tiers work? Here are your four key numbers, and how those influence the final cost:
The weight breakpoints that jump fees
The width, depth, and height dimensions you must consistently measure in inches
The exact extra fees each airline imposes, typically for every bag and every size and weight violation
Carrier-specific waivers or lower fees for premium status, special items like musical instruments, or the occasional firewall that keeps price excursions down.
Weight Comes First
Overweight fees are often the stickiest point of baggage charges in the United States, and that starts with the fact that the base fee is not applied to bags over 50 lbs (23 kgs). Flying on American Airlines? Flexible in which bags you check? Good. Because when your bag tops that limit, you’re charged extra. Double that if it's over 70 lbs (32 kgs); but there’s no fee if you're in Flagship First or Flagship Business. United stops taking baggage over 100 lbs (45 kg); other carriers have the same maximum limit. And if you're the millimeter over? No deal. Those carriers move you up a band, to a higher fee, while Delta is the same at 100 and above. Same story at Southwest, which is a bit more permissive with larger bags, and moves you up a tier at 70 up to 100 lbs - but don't expect any of this to be on your bag fee waiver. So, frequent flyer, read on.
Then Come the Dimensions - in Their Own Way
Most airlines state a maximum checked bag size, not on a case-by-case basis, of 62” linear dimensions and no bag above 80. And United is clear that any bag over 115 inches is a no-go. This has nothing to do with weight - them's the rules. Delta is another way outright: if you’re at 80 inches, you’re paying an extra $200. American isn’t at all ambiguous: if one of these dimensions holds, you’re paying the $150 oversized fee. No halfway. So don’t take the bag without measuring it first, or standing in line might not be your biggest problem.
When Both Applies, the Higher Fee Comes First
All three of the major American airlines - American, Delta, and United - charge both fees when a bag falls into both categories, if only because those tend to be frequent offenders that have incurred baggage fees. And if only one ticket is charged? It’s generally not for nothing. One focuses on the system-based fee if the bag exceeds the free tiers, says to take either one for $250. Moving to a similarly priced United, you’ll pay whichever tier is higher, sized to save on fees. Delta applies fees for each violation, with charges that can add up. Southwest’s “free-gate check” door offers a subtle drop: operate within the bands, even if it's a bigger monstrosity, and you won't pay. It’s a minor cheat, but it underscores how tricky these rules can get.
