So, you're planning a trip with Southwest Airlines, and you're wondering, just how big can my luggage be without incurring those dreaded extra fees? It's a common question, and getting it right can save you both money and a significant amount of stress at the airport. While Southwest used to be famous for its "Bags Fly Free" policy, recent changes (as of May 28, 2025, for tickets purchased on or after that date) mean it's more important than ever to understand their baggage dimensions and weight limits.
Let's dive into a comprehensive, step-by-step guide to ensure your bags are perfectly compliant for your next Southwest adventure!
Understanding Southwest Airlines' Baggage Policies: A Step-by-Step Guide
Step 1: Let's Get Started! Do You Know Your Baggage Type?
Before we measure a single bag, let's identify what kind of luggage you're planning to bring. Are you looking to carry a small bag onto the plane with you, or are you checking a larger suitcase? Southwest has different rules for:
Carry-on Bags (the ones that go in the overhead bin)
Personal Items (the smaller bag that fits under the seat in front of you)
Checked Bags (the ones you hand over at the counter)
Knowing which category your bag falls into is the absolutely crucial first step!
Step 2: Mastering the Carry-On: Overhead Bin Essentials
Your carry-on bag is your trusty companion for essentials, but it needs to fit comfortably in the overhead bin.
Sub-heading: What are the dimensions for carry-on bags?
Southwest Airlines states that carry-on bags must not exceed 24 inches (length) x 16 inches (width) x 10 inches (height).
Sub-heading: Important Considerations for Carry-Ons:
These dimensions include wheels and handles! Don't forget to account for these protruding parts when measuring your bag. Many people make this mistake and end up with an oversized carry-on.
Weight Limit: Southwest generally does not specify a weight limit for carry-on bags, but you must be able to lift your bag into the overhead bin without assistance. If you can't, it's likely too heavy and may need to be checked.
If your carry-on is found to be oversized at the gate, you may be required to gate-check it, potentially incurring a checked bag fee if you've already utilized your allowance.
Step 3: The Personal Item: Your Under-Seat Sidekick
Alongside your carry-on, you're allowed one personal item. This is fantastic for keeping your most important belongings close at hand during the flight.
Sub-heading: What are the dimensions for personal items?
While Southwest doesn't always specify exact dimensions on their main policy pages, common unofficial guidelines and what is generally accepted is around 18.5 inches (length) x 8.5 inches (width) x 13.5 inches (height). The key requirement is that it must fit completely under the seat in front of you.
Sub-heading: Examples of Personal Items:
A purse or handbag
A laptop bag or briefcase
A small backpack
A pillow
A camera bag
Remember, if it doesn't fit under the seat, it's not a personal item!
Step 4: Decoding Checked Baggage: The Bigger Picture
This is where things can get a bit more complex, especially with the recent policy changes. Southwest has been known for its generous checked bag policy, but it's vital to stay updated.
Sub-heading: Standard Checked Bag Dimensions and Weight:
For most passengers, each checked bag must adhere to the following:
Maximum Weight: 50 pounds (23 kg) per piece.
Maximum Size: 62 linear inches (length + width + height). To calculate this, you'll add the length, width, and height of your bag together. Again, this includes wheels and handles!
Sub-heading: The New Checked Bag Fees (Effective May 28, 2025):
First Checked Bag: $35
Second Checked Bag: $45
Third (and subsequent) Checked Bags: $150 per bag
This is a significant change, so be sure to factor these costs into your travel budget!
Sub-heading: Exceptions and Waivers for Checked Bag Fees:
Southwest does offer some exemptions to these new fees:
Business Select Fares: Passengers who book Business Select tickets will still receive two free checked bags.
Rapid Rewards A-List Preferred Members: These elite loyalty members will also receive two free checked bags.
Southwest Co-branded Credit Cardholders: Many Southwest credit cards offer one free checked bag as a perk. Check your specific card benefits.
Active-Duty Military Personnel: With a valid military ID, active-duty military passengers are exempt from the two-piece baggage limit and will not be subject to excess, oversized, or overweight baggage charges, provided bags do not exceed 100 pounds and 80 inches in size.
Hawaii Inter-island Travel: For residents of Hawaii traveling between the islands, two free checked bags are still allowed.
Always verify your eligibility for these waivers!
Step 5: Measuring Your Luggage Accurately: The DIY Approach
This is perhaps the most crucial step to avoid surprises at the airport. Don't eyeball it!
Sub-heading: Tools You'll Need:
A tape measure (a flexible cloth tape measure is best for soft-sided bags, but a standard metal one works too).
A weighing scale (a luggage scale is ideal, but a bathroom scale can work for larger bags – just weigh yourself, then weigh yourself holding the bag, and subtract).
Sub-heading: How to Measure (Length + Width + Height):
Lay your bag flat: Place your suitcase on a flat surface.
Measure the Length: Measure from the very bottom to the very top, including any wheels and handles (when fully retracted).
Measure the Width: Measure across the widest part of the bag.
Measure the Height/Depth: Measure from the front to the back of the bag at its thickest point.
Add them up: Sum these three measurements. For a checked bag, this total must be 62 inches or less. For a carry-on, ensure each individual dimension is within the limits (24x16x10 inches).
Sub-heading: How to Weigh Your Bag:
Use a luggage scale: If you have one, simply hook it to your bag's handle and lift.
Bathroom scale method:
First, weigh yourself.
Then, weigh yourself while holding your packed bag.
Subtract your weight from the combined weight to get your bag's weight.
Do this for ALL bags you plan to check and carry on! Better safe than sorry.
Step 6: Understanding Oversize and Overweight Baggage: When Things Get Pricey
If your bags exceed the standard limits, Southwest has specific surcharges.
Sub-heading: Overweight Baggage Fees:
51-70 pounds (24-32 kg): $100 per bag
71-100 pounds (33-45 kg): $200 per bag
Bags over 100 pounds: Will not be accepted as checked baggage and must be shipped as Air Cargo (which has its own requirements).
Sub-heading: Oversize Baggage Fees:
63-80 linear inches (160-203 cm): $200 per bag
Bags over 80 linear inches: Cannot be checked as baggage (unless you're active military or it's certain sports equipment, see below).
Important Note: If a bag is both overweight and oversized, you will generally only be charged one fee, whichever is higher, as long as the bag does not exceed 100 pounds and 80 linear inches.
Step 7: Special Items: Sports Equipment, Musical Instruments, and More
Southwest has specific policies for various special items. These often have different size and weight allowances and may incur specific fees.
Sub-heading: Sporting Equipment:
Many common sports items (golf clubs, skis, snowboards, surfboards, etc.) can count as one of your checked bags if they meet certain criteria.
However, some may have specific fees or size/weight waivers. For instance, surfboards can be accepted for a fee of $75 on most flights, but travel free as a substituted checked bag on Hawaiian Inter-island flights.
Always check Southwest's specific policy for your particular piece of sports equipment on their official website.
Sub-heading: Musical Instruments:
Small instruments can often be carried on if they fit in the overhead bin or under the seat.
Larger instruments that exceed carry-on dimensions but still fit in the cabin (e.g., cellos) may require the purchase of an additional seat.
Instruments that are too large for the cabin can be checked, but special oversize/overweight fees may apply if they exceed standard checked bag limits (up to 150 linear inches and 165 pounds for instruments).
The general rule is: if it's valuable or fragile, try to carry it on or buy an extra seat if permitted.
Step 8: International Travel Considerations
While Southwest primarily operates within the U.S., they do have international routes.
If any portion of your itinerary includes an international flight, you must check your luggage at the ticket counter – curbside check-in is not permitted.
Baggage for international flights will not be accepted less than 60 minutes prior to scheduled departure (75 minutes for Aruba).
If you have a connecting international flight into the U.S., you will need to claim your checked baggage at your first point of entry into the U.S. to clear Customs, and then re-check it.
Always factor in extra time for international connections.
10 Related FAQ Questions (How to...)
Here are some quick answers to common "How to" questions regarding Southwest Airlines baggage:
How to avoid checked bag fees on Southwest Airlines?
You can avoid checked bag fees if you book a Business Select fare, are a Rapid Rewards A-List Preferred member, hold a qualifying Southwest co-branded credit card (which often grants one free checked bag), or are active-duty military personnel with a valid ID.
How to measure luggage for Southwest Airlines accurately?
To measure accurately, use a tape measure to get the length, width, and height of your bag, ensuring you include wheels and handles. For checked bags, add these three dimensions to get the total linear inches. For carry-ons, each dimension must individually meet the limit.
How to weigh luggage for Southwest Airlines at home?
Use a luggage scale for precision. If you don't have one, use a bathroom scale: weigh yourself, then weigh yourself holding the packed bag, and subtract your weight to find the bag's weight.
How to pack efficiently to meet Southwest's baggage limits?
Roll your clothes tightly, use packing cubes to compress items, wear your heaviest items (like boots or jackets) on the plane, and consider if you truly need everything or if some items can be purchased at your destination.
How to check special items like sports equipment on Southwest?
Check Southwest's official website for specific sports equipment policies. Many items are accepted as checked bags, often counting towards your allowance, but some may incur special fees if oversized or overweight.
How to handle musical instruments on Southwest Airlines?
Small instruments can be carried on if they fit in the overhead bin or under the seat. Larger instruments may require purchasing an additional seat or can be checked, subject to specific dimension and weight limits and potential fees.
How to confirm the latest Southwest baggage policy?
Always check the official Southwest Airlines website (Southwest.com) or their mobile app for the most up-to-date baggage policies, as they can change.
How to prepare for gate-checking a carry-on on Southwest?
If your carry-on is oversized or if the flight is full, you might be asked to gate-check it. Be prepared by having any essential medications, valuables, or documents in your personal item that will stay with you.
How to retrieve checked baggage after an international flight with Southwest?
For international arrivals into the U.S., you must claim your checked baggage at your first point of entry to clear U.S. Customs, even if you have a connecting flight. You will then re-check your bags for your onward journey.
How to contact Southwest Airlines for baggage questions?
You can typically find contact information for Southwest Airlines customer service on their official website (Southwest.com), usually under a "Contact Us" or "Help Center" section. They offer phone support and sometimes online chat.
