Carry-on Bag Size Restrictions & Policy for United Airlines

United airplane in the sky

It’s always wise to check the carry-on luggage policies of an airline before you fly, if only to avoid having to check your carry-on at the departure gate. United Airlines' carry-on policy doesn’t differ significantly from other airlines, but it does have rules you should be aware of, including the airline's under-seat dimensions, prohibited items, and personal item dimensions. Whether you’re flying United Express also impacts what you can carry onto one of United’s planes. Here we’ll go over United Airlines carry-on size rules and how to make the most of them for your trip.

Carry On Weight and Size restrictions

United carry-on rules allow you to bring one carry-on and one personal item, such as a purse, camera case, or laptop bag. There are exceptions to this rule, such as taking a United Express flight or flying Basic Economy on a non-transatlantic flight

United Airlines Carry-on Size Restrictions

Carry-on luggage for a United Airlines flight must be no larger than 9 inches X 14 inches X 22 inches (22 cm X 35 cm X 56 cm). When measuring, remember these dimensions include the luggage’s wheels and handles. If your carry-on luggage does not meet United carry-on rules, you’ll have to check your bag at the departure gate and pay a $35.00 gate handling fee plus the applicable checked bag fee.

carry on size restrictions

While United’s carry-on policy has limited luggage size, there is no maximum weight allowance. If you can fit it into your carry-on bag and it’s acceptable to bring on board, it doesn’t matter how much carry-on items weigh. Be aware, however, that you have to store the carry-on in the cabin’s overhead compartment by yourself, so make sure you can handle the weight.

United Airlines Personal Item Dimensions

Personal items such as backpacks, laptop bags, and purses are allowed on United flights, as long as they can be safely stowed under the seat in front of you. Before your flight, check to see if your personal item meets United Airlines’ under-seat dimensions. Personal items can not be larger than 9 inches X 10 inches X 17 inches (22 cm X 25 cm X 43 cm).

personal item dimensions

As with carry-on luggage, United’s carry-on rules for personal items do not consider weight.

United Express Carry-On Rules

United Express flights are operated by regional airline partners, who typically use smaller aircraft with less overhead space than United’s regular aircraft. Often larger carry-on bags and roller bags will not fit in the overhead bins of Express aircraft. In such cases, you will have to check your bag for free at the gate, and United will return it to you just outside the aircraft at your destination. Be sure to remove any vaping devices or e-cigarettes from carry-on should the luggage need to be checked.

United Basic Economy Restrictions

Travelers with Basic Economy tickets can only board with one personal item and no carry-on bag unless the following criteria are met:

  • You are traveling on trans-Atlantic flights to or from the US, Mexico, Central American, El Salvador, Panama, or South America.
  • You are on a trans-Pacific flight to or from the USA.
  • You are a MileagePlus® Premier® member or companion traveling on the same reservation.
  • You are the primary card member of a qualifying MileagePlus credit card or Star Alliance™ Gold member.

What Can I Bring On Board a United Airlines Flight?

United Airlines allows passengers to carry liquids, gels, and aerosols in their carry-on bags, as long as such substances meet TSA’s liquids rule. All liquids, gels, and aerosols are limited to 3.4-ounce containers (100 milliliters), and all such containers must fit into one clear, sealable quart-size bag. This restriction includes shampoo, conditioner, toothpaste, mouthwash, and lotion.

In addition to your carry-on bag and personal item, you can board a United Airlines flight with the following items:

  • Umbrella
  • Jacket or coat
  • Food and drink purchased in the airport after going through security
  • Merchandise purchased in the airport, such as magazines, books, cameras, or souvenirs
  • Diaper bags
  • Breast milk pumps
  • FAA-approved child restraint system or safety seat
  • Assistive devices such as canes crutches, and collapsible wheelchairs
  • Medical devices for prescription medication
  • Portable oxygen concentrators
  • Pet carriers (service charges will apply)
  • Vaping pens and e-cigarettes (which cannot be charged or used during flight)
  • Lithium batteries removed from their devices, insulated, and protected against crushing or puncturing
  • Avalanche packs with  lithium batteries under 100WH
  • Liquid nitrogen in vented bags if the item stored is not dangerous (such as biohazards)
  • Powered air-purifying respirators with batteries removed and stored prior to transport

You can bring small musical instruments such as guitars and violins on board only if the instrument is packed in a hard case and the flight has space in an overhead compartment or under the seat in front of you.

United Airlines Prohibited Items

Any item restricted by the TSA violates United Airlines’ carry-on policy. We recommend checking your packed items with the TSA’s What Can I Bring webpage before flying. United airlines prohibited items for carry-on specifically include the following:

  • All matches and lighters (if departing from Beijing)
  • Smart bags without removable lithium batteries
  • Powder-based substances over 12 fluid ounces (350 milliliters). Exceptions are made for medically prescribed powders, baby formula, human remains, and duty-free powders, but such items should be sealed in tamper-evident bags. 
  • Self-balancing or self-riding bags
  • Camping equipment that contains any kind of fuel
  • Self-defense sprays (mace, pepper sprays, tear gas)
  • Torch lighters
  • Explosives (fireworks, gunpowder, flares, flare guns, or novelty items)
  • Ready-to-eat meals that include flameless heaters
  • Shock absorbers
  • Tasers
  • Knives, guns, or other weaponry
  • Sporting equipment which could be used as a weapon
  • Avalanche packs containing 1.4s or CO2
  • Recalled, damaged, or defective batteries

Certain everyday household items also fall under United Airlines prohibited items list, and cannot be packed in carry-on or checked bags:

  • Aerosolized spray paint, household cleaners and pesticides
  • Bleach
  • Drain cleaners
  • Epoxy
  • Fuel
  • Gel fuel
  • Glue
  • Insecticides
  • Matches (the strike-anywhere kind)
  • Paint 
  • Torch lighters
  • Spray starch

Recreational self-propelled vehicles and devices designed to carry people and goods have the potential to injure passengers and crew, and as such are not allowed as carry-on. Such devices include the following:

  • Hoverboards
  • Airboards
  • Skateboards
  • Self-balancing wheeled devices
  • Battery-assisted bicycles
  • Wheeled vehicles
  • Electric scooters
  • Riding or motorized suitcases

Those are United Airlines carry-on rules. Remember carry-on policies are subject to change over time. If you're unsure, check with United directly to ensure your carry-on luggage and packed items meet the airline’s current requirements.

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