How Strict Is United About Carry-on Size? 2026

So how strict is United Airlines about its carry-on size?

Just like many other big U.S. airlines, United allows you to bring two pieces of hand luggage: one carry-on bag and one personal item, such as a purse, small backpack, briefcase, or laptop bag. The carry-on size limit is 22 x 14 x 9 inches (56 x 35 x 23 cm).

This post will walk you through all the details about United Airlines carry-on policies, from understanding how strict they really are about enforcing the size limit to what to do if your carry-on is just a tad too big.

Let’s dive in.

How Strict Is United Airlines With Carry-on Size Limits?

According to United’s website, unless you’re flying to South America, across the Atlantic, or across the Pacific, most passengers (except those flying Basic Economy) can bring one free carry-on bag with a maximum size of 22 x 14 x 9 inches (56 x 35 x 23 cm).

This dimensions includes handles, wheels, and straps, so no cheating.

The good news? You can also bring a personal item (like a backpack, laptop bag, or small purse) that fits under the seat in front of you.

The ideal size for this is 9 x 10 x 17 inches (23 x 25 x 43 cm). 

Both items are free of charge, as long as they meet the size requirements.

But here’s the catch: if your bag is large and doesn’t fit in the overhead bin or under the seat, say adieu to your carry-on.

You’ll have to check it, and depending on your ticket type, you might need to pay extra fees, especially if it’s gate-checked.

Suggested: What is the Best Carry On Bag For United Airlines?

How Strict Is United Airlines in Real Life?

In real life United is slightly strict about its carry-on size limits.

If your bag looks even a little too big, they’ll likely ask you to place it in the luggage sizer at the gate.

But here’s a pro tip: the sizer itself is about 23 x 15 x 10 inches (58 × 38 × 25 cm) for carry-ons and 18 x 11 x 9 inches (46 × 28 × 23 cm) for personal items.

That means there’s a tiny bit of wiggle room, just don’t push your luck.

If you’re flying Basic Economy, though, beware.

You’re only allowed one personal item, and United is very strict about this.

Any additional bags will have to be checked, and you’ll likely pay extra for the privilege.

What Else Can You Bring Onboard?

Besides your carry-on and personal item, United lets you bring few additional items onboard for free:

• A jacket or umbrella
• A camera bag
• Food or items bought at the airport
• Assistive devices (like collapsible wheelchairs or medical equipment)
• An FAA-approved child restraint system or safety seat
• Reading material, like books and magazines
• A diaper bag or breast pump
• A pet carrier (though fees apply for in-cabin pets)

Liquids and Toiletries: The TSA 3-1-1 Rule

Toiletries are essential things to always have inside your bag, no matter which airline you’re flying with.

If you’re planning to bring liquids and toiletries on your next United flight, you’ll need to stick to the TSA 3-1-1 rule for liquids, because they are the guys that are responsible for what you ca and can’t bring on airport with and from the U.S.

Each container or bottle must be 3.4 ounces (100 milliliters) or less.

All containers must fit in a single quart-sized bag.

Place larger quantities of liquids in your checked baggage.

Checked Luggage: What You Need to Know

Even if you’re traveling carry-on only, it’s good to know United’s checked baggage rules just in case.

Weight Limits by Class:

• United Economy: 50 pounds (23 kilograms)
• United Business / First / Polaris: 70 pounds (32 kilograms)

Oversized or Overweight Bags:

United won’t accept bags over 115 inches (length + width + height) or 100 pounds (45 kilograms).

Exceptions include musical instruments (up to 165 pounds) and assistive devices.

If your bag is oversized or overweight, expect to pay extra fees.

Final Thoughts: Stay Within the Limits

United Airlines is moderately strict, about its carry-on size limits, especially for Basic Economy passengers. 

While there’s a bit of flexibility with the sizer, it’s always better to stay within the official size especially if you have a Basic Economy ticket or flying in the peak season.

To avoid stress or any extra fees, double-check your bag’s dimensions before heading to the airport. 

Stick to the rules, and you’ll have a smooth, hassle-free travel experience.

I hope this helps.

Happy travels.

United Airlines Carry-On FAQ

• What happens if your carry-on is slightly over United’s size limit?
  If it doesn’t fit in the overhead bin or the sizer, United will ask you to gate-check it, and you will need to pay charges depending on your fare type.
• Does United measure carry-on bags or just eyeball them?
  Most of the time, agents take a look at the bag. If a bag looks too large, you’ll be asked to place it in the sizer.
• Are expandable carry-on bags allowed if they fit in the sizer?
  Expandable carry-ons are allowed as long as they fit within the sizer when expanded.
• Are soft-sided carry-ons treated differently from hard-shell bags?
  United treat bags the same, but soft-sided bags have a slight advantage because they can be squeezed into overhead bins or sizers more easily.
• Does United enforce carry-on size limits more strictly at the gate?
  Yes. Enforcement usually happens at the gate rather than at check-in.
• Are carry-on rules enforced more strictly on full flights?
  On busy flights, gate agents are more likely to enforce size limits to manage overhead bin space.
• Are carry-on size limits stricter on smaller United aircraft?
  Smaller aircraft often have limited overhead space, so the agent will likely be more strict to manage the space.

Related :

• How strict is United about personal item?
• How strict is American Airlines with carry-on?
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Gargie, is writer, traveler & a digital marketing specialist passionate about traveling and exploring new cultures. She is a savvy traveler who likes to pack light, testing various luggage brands and seeking out budget-friendly airline options. Gargie enjoys creating unique recipes when she’s not on the go.