Southwest Airlines Carry On Rules and Size Limits

Traveling with Southwest Airlines offers more flexibility than many other carriers, but knowing the specifics of the Southwest airlines carry on rules is essential for a smooth boarding process. Understanding the exact dimensions and personal item requirements ensures you avoid unexpected gate checks or fees before your flight begins.

Understanding Southwest Airlines Carry On Rules for Size and Weight

Southwest Airlines has long been known for its generous baggage policies, though recent updates in 2025 have shifted the landscape for checked luggage. Despite these changes, the Southwest airlines carry on rules remains one of the most traveler friendly in the industry. Every passenger is permitted to bring one carry on bag and one personal item at no additional cost. This applies to all fare classes, from Wanna Get Away to Business Select, making it a reliable choice for budget conscious travelers who want to avoid the hidden fees often found with ultra low cost carriers.

While Southwest does not strictly enforce a weight limit for domestic carry on bags, there is a practical requirement that every traveler should keep in mind. You must be able to lift your bag into the overhead bin unassisted. This is a safety measure to ensure that flight attendants are not strained and that boarding continues at a brisk pace. If you are traveling with a dense item like a Leather Duffel Bag, ensure you can comfortably hoist it above your head before reaching the gate. For those accustomed to other airlines, you might find the lack of a scale at the gate refreshing, but size dimensions are still strictly monitored by ground staff.

It is important to note that the Southwest airlines carry on rules are subject to the available space on the aircraft. Southwest exclusively flies Boeing 737 aircraft, which have specific cabin configurations. While the airline strives to accommodate all carry on bags, full flights may result in later boarding groups being asked to gate check their larger items. Knowing how to pack efficiently and choosing the right gear can make the difference between keeping your bag with you and seeing it disappear into the cargo hold at the last minute. You can find excellent options in this collection of The Best Carry On Bags of 2025 to ensure your luggage meets these standards.

Maximum Dimensions for Southwest Carry On Bags

The specific size limit for a carry on bag on Southwest is 24 inches long, 16 inches wide, and 10 inches tall. These measurements are inclusive of all external attachments, which means you must account for wheels, telescoping handles, and side pockets when measuring your luggage. Many manufacturers claim their bags are carry on sized, but they often exclude the wheels in their listed dimensions. For Southwest, the total exterior volume is what matters most to ensure the bag fits securely within the overhead bin compartments of the Boeing 737 fleet.

If your bag exceeds these dimensions, it may not fit in the overhead bins, especially on older aircraft models like the 737 700. On these planes, bags must often be placed sideways, which consumes more space and limits the number of passengers who can store their luggage. In contrast, the newer 737 MAX 8 aircraft feature Space Bins that allow bags to be stowed on their sides, significantly increasing capacity. Regardless of the aircraft type, staying within the 24 by 16 by 10 inch limit is the only way to guarantee your bag is compliant with Southwest airlines carry on rules. For more details on how this compares to other carriers, you might want to read about American Airlines Carry On Luggage Size Requirements to see the subtle differences in allowed width and height.

The Leather Duffel Bag from Luhxe is an excellent example of a stylish yet functional piece that fits within many travel contexts. Priced at $130, this bag provides a sophisticated look for business or leisure travel. Because it is a soft sided bag, it offers a bit of flexibility when fitting into tight overhead spaces, provided you do not overpack it beyond the 10 inch depth limit. It is a durable choice for those who prefer the aesthetic of leather over standard ballistic nylon suitcases.

Southwest Airlines Personal Item Rules and Requirements

In addition to your main carry on, Southwest airlines carry on rules allow for one personal item. This item must be small enough to fit completely under the seat in front of you. The typical maximum dimensions for a personal item on Southwest are 18.5 inches by 8.5 inches by 13.5 inches. Common examples of personal items include small backpacks, laptop bags, purses, briefcases, and small tote bags. This secondary bag is crucial for keeping your essentials like snacks, electronics, and travel documents within reach during the flight.

When selecting a personal item, it is wise to choose something versatile that can serve multiple purposes once you reach your destination. The Luhxe 3 in 1 Tote Bag, priced at $79.99, is specifically designed for the modern traveler. It functions as a structured tote that can easily slide under an airplane seat while maintaining a professional appearance. For travelers who are also looking at other airlines, understanding the United Airlines Carry On Luggage Size Rules can help you see how a versatile tote like this one works across different fleet types and boarding requirements.

It is worth noting that if you bring a garment bag, it will count as your carry on bag rather than a personal item, unless it is exceptionally small. Southwest flight attendants are generally helpful with storage, but they cannot allow items to obstruct the floor area or the space under the seat during takeoff and landing. Ensuring your personal item stays within the 18.5 inch length ensures you have enough legroom to remain comfortable during the journey. For those who need to maximize every inch, checking out Space saving travel bags for carry on can provide additional inspiration for your gear setup.

How Southwest Boarding Groups Affect Your Overhead Bin Space

One of the most unique aspects of flying with Southwest is their open seating policy. Unlike other airlines that assign seats and zones, Southwest assigns a boarding position consisting of a letter (A, B, or C) and a number (1 through 60). This system has a direct impact on the Southwest airlines carry on rules in practice. Those in the A group, particularly those with Business Select fares in positions A1 through A15, almost always find ample overhead bin space near their chosen seat. As the boarding process continues through the B group and into the C group, the available space in the overhead bins diminishes rapidly.

If you are assigned a position in the C group, there is a significant chance that the overhead bins will be full by the time you board. In these instances, flight attendants will often begin requiring passengers to gate check their carry on bags. While gate checking is free, it means you will have to wait at the baggage carousel at your destination to retrieve your luggage. To avoid this, many frequent flyers utilize EarlyBird Check In, which automatically checks you in 36 hours before departure to secure a better boarding position. This strategy is particularly effective for those who do not want to worry about bin availability.

The type of aircraft you are flying also plays a role. Southwest has been modernizing its fleet with the Boeing 737 MAX 8, which features significantly larger Space Bins. These bins are designed to hold six standard sized carry on bags vertically, rather than the four bags that fit horizontally in older bins. If you find yourself on a MAX 8, your chances of finding space are much higher even in the later boarding groups. However, since Southwest rotates its fleet constantly, it is best to be prepared for the smaller bins found on their 737 700 models by arriving at the gate early and following the Southwest airlines carry on rules closely. To learn more about selecting the right gear for frequent travel, check our guide on The Best Luggage Carry On for Frequent Travelers.

Prohibited Items and TSA 3-1-1 Liquid Rules on Southwest

Navigating security is the first hurdle in following the Southwest airlines carry on rules. Southwest adheres strictly to the TSA 3-1-1 rule for all liquids, aerosols, gels, creams, and pastes. This means each item must be in a container that is 3.4 ounces (100 milliliters) or less. All of these containers must fit comfortably inside a single, clear, quart sized plastic bag. Each passenger is limited to one such bag. If you have larger quantities of liquids, they must be placed in checked luggage or discarded at the security checkpoint. For official and updated lists of what can pass through security, you should consult the TSA Liquids Rule page.

Beyond liquids, there are several categories of items that are strictly prohibited from carry on bags for safety reasons. These include explosives, flammable materials, and toxic chemicals. While you might not think your everyday items fall into these categories, certain aerosols like spray paint or large cans of hairspray are often flagged. Sharp objects are also restricted. While small scissors with blades shorter than 4 inches are generally allowed, knives and razor blades must be checked. An exception exists for blades less than 2.36 inches in some jurisdictions, but it is always safer to check them to avoid delays. For a complete list of prohibited items, the TSA Prohibited Items list is the gold standard for travelers.

When packing your personal item, like the Hoodie Backpack, it is helpful to keep your liquid bag in an easily accessible pocket. The Hoodie Backpack, priced at $79, is a unique option that blends the comfort of a hoodie with the utility of a backpack. It is an ideal personal item for those who prioritize comfort during long flights. By keeping your 3-1-1 bag in an outer pocket of your backpack, you can quickly remove it for screening without having to dig through your entire carry on bag. This efficiency helps keep the security line moving and reduces the stress of travel.

Tips to Avoid Gate Checking on Southwest Flights

Gate checking can be a major inconvenience, especially if you have a tight connection or items you need immediately upon landing. To minimize the risk of being forced to check your bag, the most effective strategy under Southwest airlines carry on rules is to secure an early boarding position. Checking in exactly 24 hours before your flight is the most common way to do this for free. Even a few seconds of delay in checking in can move you from the B group to the C group. If you are a frequent traveler, consider the Southwest Rapid Rewards Priority Credit Card, which offers four upgraded boardings per year when available.

Another tip is to use a soft sided bag that can be slightly compressed if the bins are crowded. Hardshell suitcases are unforgiving and will be the first ones to be rejected if the bin is just a fraction of an inch too full. A bag like the Luhxe Leather Duffel Bag offers that slight bit of give that can help it slide into a tight spot. Additionally, if you see that you are in a late boarding group, try to board as soon as your group is called. Standing near the gate area when your letter is nearing will ensure you are among the first in your group to get on the plane and scan for remaining overhead space.

If you are traveling as a family, try to consolidate smaller items into one larger carry on and use the remaining personal item slots for smaller bags that must stay with you. Southwest allows one stroller and one car seat per child to be checked at the gate for free, which does not count against your carry on allowance. By managing your gear wisely, you can ensure that your most valuable items stay in the cabin with you. For more packing strategies, explore our collection on How to pack more in a carry on luggage to maximize your available space.

Comparing Southwest Baggage Policies to Other Major Airlines

When you look at the Southwest airlines carry on rules in comparison to Delta, United, or American, the biggest difference lies in the fare structure. Many major airlines have introduced Basic Economy fares that either restrict carry on bags entirely or charge a significant fee for them. On Southwest, every fare includes a carry on and a personal item for free. This makes the headline price of a Southwest ticket much more transparent than the competitors, where you might have to add $30 to $60 round trip just to bring a standard suitcase.

Furthermore, Southwest's dimension limits are slightly more generous than some other carriers. While many airlines limit carry on height to 22 inches, Southwest allows up to 24 inches. This extra two inches can be the difference between needing to check a bag and being able to carry it on. However, it is vital to remember that if you are switching from a Southwest flight to an international carrier or a smaller regional jet on a different airline, your bag might be too large for their more restrictive rules. For a detailed breakdown of these differences, you can review the Carry On Luggage Size Southwest Rules blog post.

In terms of checked baggage, Southwest was famously the last major US airline to offer two free checked bags. While this changed for standard fares in 2025, the culture of the airline still leans toward being more accommodating than the legacy carriers. If you are a member of the military on active duty, Southwest often provides additional baggage allowances that exceed the standard Southwest airlines carry on rules. Always check the latest updates on the Southwest Help Center before you head to the airport to ensure you have the most current information for your specific traveler profile.

Strategies for Packing Efficiently within Southwest Limits

To truly master the Southwest airlines carry on rules, you must develop a packing strategy that utilizes every cubic inch of your allowed volume. Roll your clothes instead of folding them to save space and reduce wrinkles. Use packing cubes to organize your items and compress them further. This is especially helpful when using a duffel bag, as it prevents items from shifting and creating bulges that might make the bag exceed the 10 inch depth limit. Many travelers find that they can fit a week's worth of clothing into a single carry on by using these methods.

Consider the weight of your bag as well. Although there is no strict weight limit, a heavy bag is harder to maneuver through the airport and lift into the overhead bin. Choose lightweight materials where possible. While leather is beautiful and durable, it is heavier than synthetic fabrics. If you choose the Leather Duffel Bag, balance its weight by packing lighter items inside. For those who need to carry electronics, use a backpack like the Hoodie Backpack to distribute the weight across your shoulders, which makes navigating the long concourses of airports like Dallas Love Field or Chicago Midway much more comfortable.

Lastly, always wear your bulkiest items on the plane. If you are traveling with a heavy coat or large boots, wearing them during the boarding process saves a massive amount of space in your carry on bag. Once you are in your seat, you can usually place your coat on top of your bag in the overhead bin or use it as a pillow. This simple trick can free up enough space to allow you to bring an extra pair of shoes or more clothing options for your trip. For more tactical advice, check out the collection on How to Organize a Carry On Bag to streamline your next journey.

The Impact of Boeing 737 Cabin Layouts on Storage

Because Southwest Airlines exclusively operates the Boeing 737, their cabin storage is more predictable than airlines with mixed fleets. However, there are still variations between the older 700 series, the 800 series, and the new MAX 8 models. The 700 series has the most limited overhead space. These bins are shorter and shallower, often requiring bags to be placed lengthwise. This means that if you have a bag that is exactly 24 inches long, it will take up a significant portion of the bin, potentially leaving less room for others. Following the Southwest airlines carry on rules becomes even more critical on these smaller planes to ensure everyone's gear fits.

The 800 series and the MAX 8 are much more accommodating. The MAX 8, in particular, was designed with the modern traveler in mind. Boeing worked with airlines to create bins that allow bags to be flipped on their sides, like books on a shelf. This design can hold up to 50 percent more luggage than previous versions. When you are booking your flight, you can often see the aircraft type in the flight details. If you have the choice, opting for a flight operated by a MAX 8 can provide more peace of mind regarding your carry on luggage. For further reading on aircraft specifics, the Boeing 737 MAX official site offers insights into these cabin improvements.

Regardless of the plane, the floor space under the seat is relatively consistent across the fleet. This is where your personal item must go. If you are seated in an exit row or the first row (the bulkhead), you will not have a seat in front of you. In these cases, all of your bags, including your personal item, must be placed in the overhead bin for takeoff and landing. This is a small trade off for the extra legroom these seats provide. Being aware of these seating nuances helps you manage your luggage according to Southwest airlines carry on rules without any surprises from the flight crew.

What to Do if Your Carry On Is Gate Checked on Southwest

Even the most prepared traveler might occasionally have to gate check their bag. If the flight attendant informs you that the bins are full, they will provide you with a green or white tag to attach to your bag. It is vital that you remove any essential medications, lithium batteries, or high value items like laptops before handing the bag over. Lithium batteries are a fire hazard in the cargo hold and must remain in the cabin. Once tagged, you will leave your bag at the end of the jet bridge just before entering the aircraft.

On Southwest, gate checked bags are typically sent to the baggage claim area at your final destination, rather than being returned to the jet bridge at your connecting city or destination. This differs from some regional carriers, so it is important to clarify with the gate agent where you should pick up your bag. While it can be frustrating, remember that Southwest does not charge for gate checking bags that are forced due to lack of space. To prepare for this possibility, always have a small bag within your carry on that contains your absolute essentials so you can easily pull it out if your main bag is checked. The Luhxe 3 in 1 Tote Bag is great for this, as it can hold your laptop and chargers while your larger duffel goes into the hold.

Finally, always keep your baggage claim ticket in a safe place. This small slip of paper is your only proof of ownership if your bag is lost or delayed. Most Southwest flights arrive without issue, but having your documentation ready will speed up the process if you need to visit the baggage service office. By staying informed and flexible, you can navigate the Southwest airlines carry on rules and any deviations from your plan with ease and confidence.