While Frontier Airlines maintains a list of requirements for all carry-on baggage, they do not have their own regulations regarding liquids. Instead, Frontier Airlines (flyfrontier.com) is bound by the regulations set forth by the Transportation Security Administration (TSA.)

Acceptable Items

When deciding what can and cannot bring on a plane, arguably the most important factor is whether or not you have checked baggage. If you’re traveling with only a carry-on bag and a free personal item, you have specific size limits and TSA regulations that provide significantly fewer options than if you were also bringing a checked bag.

The perks of checked luggage are that you can put all kinds of things in there that you can’t put in your carry-on luggage. Large sports equipment (eveything from baseball bats to snowboards), wheelchairs, car seats, strollers, large musical instruments, liquid containers of any size and various firearms and knives (regualtions on these can vary depending on your destination) can all be checked. The thing you have to be most concerned about in this case is overweight baggage. Your baggage allowance is typically 50lbs per checked bag/item. If you go over the weight limit you either have to redistribute the items somehow, or you’ll be charged an additional fee. A good practice is to check-in at the ticket counter kiosk early so you have time to figure all of this out at the airport with time to make it to your gate.

While checking luggage is nice for bringing larger, bulkier items you normally cannot carry on, traveling with just carry-on luggage can also be very convenient. You get to avoid baggage fees and don’t have to worry about your bags getting lost on the way, all for the price of just using a carry-on size shampoo. Frontier Airlines carry-on allowance gives you two free carry-on items: your carry on bag, which will be stored in the overhead bin, and your personal item, something small like a diaper bag, assistive device, small backpack or purse that can be nestled under the seat in front of yours. Your carry-on bag must be within the standard dimensions of 22”x14”x9” linear inches in order to fit properly. If you bring oversized baggage or a second bag you could get slapped with another bag fee and be forced to check the bag anyway.

Additionally, large coats or suits/dresses on hangers can sometimes be stored in the captain’s closet, but you should contact your airline or call center first to be sure.

According to the TSA baggage policy, liquids, aerosols and gels are acceptable on board airplanes. However, the quantity of the items are subject to limitations set forth in the "3-1-1 Liquids Rule."

TSA's 3-1-1 Rule

TSA's guideline regarding carry-on liquids states that a passenger may bring aboard liquids contained in 3.4 ounce (or less) bottles. The bottles must be placed in a clear, plastic, zip-top, one-quart-sized bag. Passengers are limited to one bag each. past the security checkpoint.

Exceptions

Liquids such as medications, baby formula and food and breast milk are allowed in reasonable quantities, even if these quantities exceed the 3.4 ounce guideline. To avoid delays, the passenger must declare these items for inspection at the checkpoint.