Airline luggage restrictions depend on the type of bag, the carrier operating the flight, the route and the fare. Personal items must fit under the seat, carry-ons must fit within the cabin limits, and checked bags are usually assessed by both linear dimensions and weight. Because wheels, handles, packed pockets and expansion panels can change a bag’s final size, check it after packing rather than relying on its product name or capacity. Which Size and Weight Rules Apply to Each Type of Luggage? Airlines treat personal items, overhead carry-ons and checked luggage as separate categories. Capacity in liters does not determine which category a bag belongs to because two bags with the same capacity may have different exterior dimensions. Personal Items: Maximum Exterior Dimensions and Underseat Fit A personal item must fit completely under the seat in front of you. Some airlines publish a specific size limit, while others use underseat fit as the main requirement. American Airlines, for example, limits personal items to 18 × 14 × 8 inches. Delta and Southwest do not publish separate personal-item dimensions but require the bag to fit under the seat. Seat supports and cabin equipment can reduce the usable space, so an “underseat” product label is not a guarantee. Measure the bag after packing and include filled pockets, bottle holders and anything attached to the exterior. Carry-Ons: Maximum Exterior Dimensions and Cabin Weight Carry-on luggage is normally stored in the overhead bin. Many major U.S. airlines use a limit of 22 × 14 × 9 inches, although some allow larger bags. Carry-on weight policies vary more widely. American, Delta, United, Southwest and JetBlue do not publish a general cabin-bag weight limit for most standard flights. Frontier allows up to 35 lb. International carriers often apply lower weight limits, so the rules of the airline operating each flight should be checked separately. Because what qualifies as a carry-on bag depends on its packed dimensions, weight and the fare allowance, a product marketed as a carry-on is not automatically accepted by every airline. Even when no limit is published, passengers may still need to lift and store the bag safely without assistance. Checked Bags: Linear Dimensions and Per-Bag Weight Most major U.S. airlines allow a standard checked bag measuring up to 62 linear inches. To calculate this figure, add the bag’s length, width and height. A common standard weight limit is 50 lb, or about 23 kg, per bag. Frontier uses a lower standard limit of 40 lb. Higher allowances may apply to certain premium cabins, routes, loyalty members or military travelers. Both limits matter. A suitcase can remain under 50 lb and still be oversized, or stay within 62 linear inches and still be overweight. How Major Airline Size and Weight Limits Compare The following table shows common published limits checked in October 2026. The allowance included with a ticket may differ depending on the fare, route, status and benefits. Airline Personal Item Limit Carry-On Size and Weight Checked-Bag Size and Weight Important Exceptions American Airlines 18 × 14 × 8 in 22 × 14 × 9 in; no general weight limit published 62 linear in; 50 lb standard Some premium cabins and routes allow heavier checked bags Delta Air Lines Must fit under the seat; no separate inch limit published 22 × 14 × 9 in; no general weight limit published 62 linear in; 50 lb standard Smaller Delta Connection aircraft may require gate-checking United Airlines 17 × 10 × 9 in 22 × 14 × 9 in; no general weight limit published 62 linear in; 50 lb standard A full-size carry-on may not be included with some Basic Economy itineraries Southwest Airlines Must fit under the seat; no separate inch limit published 24 × 16 × 10 in; no general weight limit published 62 linear in; 50 lb standard Checked-bag fees and benefits depend on the fare and traveler status JetBlue 17 × 13 × 8 in 22 × 14 × 9 in; no general weight limit published 62 linear in; 50 lb standard Allowances and fees vary by fare and traveler benefits Frontier Airlines 18 × 14 × 8 in; up to 35 lb 24 × 16 × 10 in; up to 35 lb 62 linear in; 40 lb standard A full-size carry-on generally costs extra unless included with the fare or benefits These figures describe size and weight limits, not the number of free bags included with every ticket. Check the booking confirmation for the actual allowance before packing. How Do Airlines Measure Luggage Against Their Limits? Airlines assess the bag brought to the airport, not its empty shape or advertised capacity. A final check at home can reveal added depth, weight or protruding parts before they create a problem at check-in or boarding. Exterior Dimensions Include Wheels, Handles, and Packed Pockets Measure luggage at its tallest, widest and deepest points. Include wheels, fixed handles, side handles and exterior pockets that protrude when filled. A soft-sided bag should rest in its natural packed shape during measurement. Pressing it flat can hide the actual depth it will occupy in a baggage sizer or overhead bin. Checked-Bag Size Uses Length Plus Width Plus Height Checked-bag limits are usually expressed in linear inches. Add the three full exterior measurements together: Length + width + height = linear dimensions A suitcase measuring 28 × 20 × 14 inches totals 62 linear inches. The individual sides do not normally have to match a standard shape, but their combined measurement must remain within the airline’s limit. Weight Limits Apply to the Fully Packed Bag The empty bag is part of the total baggage weight. This matters on airlines that weigh cabin luggage because a lighter bag leaves more of the allowance for clothing, electronics and travel essentials. The Faro Light Backpack 0.4 weighs approximately 0.43 kg and holds 20L, providing compact space for a lightly packed one- or two-day trip. Its removable back panel allows travelers to reduce the structure when a more minimal setup is preferred. At 28 × 16 × 46 cm, its compact shape may be easier to position under a seat, although the packed bag must still be checked against the airline’s personal-item limit. Water-repellent Cordura nylon also helps protect the contents from light rain and splashes. Weigh luggage only after packing every item you plan to bring. Moving a heavy item into a personal bag will not help when the airline applies one combined cabin weight limit. Expanded Bags Are Measured at Their Expanded Size Opening an expansion zipper increases the bag’s usable space and changes its exterior dimensions. Airlines measure the expanded, packed form rather than the smaller base configuration. The Blast Pro 38L Travel Backpack measures 31 × 20.5 × 42 cm in its 28L form. Expanding it to 38L increases the depth to 25 cm. Travelers can select the capacity that stays within their airline’s depth limit and use the adjustable divider and compression system to organize the load. The backpack weighs approximately 1.2 kg empty. Its ventilated shoe compartment can be folded away when it is not needed, leaving a more flexible main compartment for clothing and other travel items. What Can You Do About Oversize or Overweight Luggage? If a packed bag exceeds the limit, the available solution depends on how far it is over, whether it is a cabin or checked bag and what the airline accepts. Repack to Meet the Limit Removing a dense item can make a meaningful difference to weight, while closing an expansion zipper or emptying an exterior pocket may reduce depth. If the airline allows a separate personal item, some essentials can be moved there. Check whether the airline weighs cabin bags separately or applies a combined allowance before redistributing anything. Check an Oversize Carry-On A carry-on that does not fit the airline’s sizer or overhead restrictions may need to be checked. Complete this at the ticket counter when possible, since waiting until the gate can result in a higher fee on some airlines. Remove medication, travel documents, valuables, spare batteries and anything needed during the flight before handing over the bag. Pay the Oversize or Overweight Fee Many airlines accept checked bags above their standard size or weight limit for an additional charge. The fee may be added to the ordinary checked-bag fee, and a bag that is both oversized and overweight may incur further costs. Fees depend on the airline and itinerary, so compare the cost with repacking or adding another standard bag. Airlines also set maximum limits beyond which a bag will not be accepted. Ship Bags the Airline Will Not Accept Shipping may be an alternative for luggage that exceeds the airline’s maximum limits or contains bulky equipment. Compare the total shipping cost, delivery time, insurance and destination access before choosing this option. Before moving belongings between cabin bags, checked luggage and a shipment, confirm what is not allowed in an airplane carry-on and which items cannot be transported in checked baggage. Shipping is not a way to bypass restrictions on dangerous or controlled materials. FAQ Does a Personal Item Count Toward the Carry-On Weight Limit? It depends on the airline. Some weigh the personal item and overhead bag together, while others treat them separately. Check whether the booking states a combined cabin weight limit. Do Airlines Weigh Cabin Bags at Check-In or at the Gate? They may weigh cabin bags at either location. Airlines with published cabin weight limits are more likely to check, but enforcement can vary by airport, route and flight. Can Two Checked Bags Share a Combined Weight Allowance? Usually not when the allowance is listed per bag. Each suitcase must stay within its own limit. Some airlines use a total-weight system, but an individual maximum may still apply to each piece. Which Airline’s Baggage Rules Apply on a Codeshare Flight? For cabin luggage, check the rules of the airline operating the flight because its aircraft and storage limits apply. Checked-bag allowances and fees may follow different interline or ticketing rules, so review the baggage allowance shown on the booking confirmation or receipt. Do Medical Devices, Strollers, and Car Seats Count Toward Baggage Limits? Qualifying assistive devices generally receive separate treatment on flights covered by U.S. accessibility rules. Airlines also commonly check strollers and child safety seats without counting them as ordinary checked bags when traveling with a child. Conditions vary, so confirm the policy before departure. Conclusion Airline luggage limits depend on both the bag category and the operating carrier. Start by deciding whether the packed bag will go under the seat, in an overhead bin or in checked baggage, then measure its full exterior and weigh it in its final state. Expansion panels, filled pockets and the bag’s own weight all count. For itineraries involving multiple airlines, checking the most restrictive applicable rule before packing can reduce the chance of repacking, gate-checking or paying an unexpected fee.