Airline guide

Flying with a dog or cat on Frontier

Frontier publishes 18 × 14 × 11 in for a soft-sided carrier under the seat. That is the number that decides whether you get on the plane. Everything below was read on the Frontier policy page, and the link to it is at the bottom.

Soft-sided maximum

18 × 14 × 11 in — length × width × height.

Hard-sided maximum

18 × 14 × 8 in

What it costs

$99 each way, per carrier

Weight limit

17 lb including the carrier

Pets per passenger

One adult dog or cat per container.

Pets per flight

Space-controlled per flight.

The one to watch on this airline

The most generous footprint published by any airline here, but the hard-sided ceiling drops to 8 in.

Which of our carriers fits under the seat on Frontier

Measured against 18 × 14 × 11 in. Length and width have to clear as published. Height gets one inch of give, because a soft side compresses — and no more than one.

Carrier Footprint (L × W) Height Pet up to Fits Price
Mr. Peanut's Gold Series Low-Profile The lowest of our zip-top cabin bags
16 × 10 in 10 in12 lb Yes $119.99 Buy
Under-Seat Carrier The long, narrow one · side entry
17 × 9 in 11.5 in14 lbFrontier counts the bag Yes $36.99 Buy
Travel Carrier — 17 in Mesh on the top and both sides
17 × 10 in 11.5 in15 lbbag weight not published Yes $35.99 Buy
Soft Carrier Bag — 17 in Opens from the top mid-flight
17 × 9 in 11.5 in14 lbFrontier counts the bag Yes $39.99 Buy
Cabin Carrier — 17 in Waterproof wipe-clean nylon · side entry
17 × 11 in 11 in11 lbbag weight not published Yes $34.99 Buy
Mr. Peanut's Gold Series Carrier Self-locking zippers · plywood base · 2.9 lb empty
18 × 10.5 in 11 in14 lbFrontier counts the bag Yes $109.99 Buy
Mr. Peanut's Gold Series Expandable Same bag to fly, opens out after you land · 3.2 lb empty
18 × 10.5 in 11 in13 lbFrontier counts the bag Yes $119.99 Buy
Mr. Peanut's Diamond Series Two expansion bays for after you land
18 × 11 in 11 in13 lbFrontier counts the bag Yes $79.99 Buy
Mr. Peanut's Platinum Series Two expansion bays · 300D nylon · 2 lb empty
18 × 10.5 in 11 in15 lb Yes $84.99 Buy
Backpack Carrier Backpack Backpack · measured lying on its back, which is the only way it goes under a seat
16.5 × 12.5 in 10.5 in13 lbFrontier counts the bag Yes $49.99 Buy
Pet Backpack Backpack Backpack · measured lying on its back, which is the only way it goes under a seat
17 × 13 in 12 in13 lbFrontier counts the bag Yes $59.99 Buy

About that weight column. Frontier weighs the bag with the animal in it, so the maker’s rating is not the number that gets you on the plane. Where we know what the empty bag weighs, we have taken it off and shown you what is actually left for your pet. Where the supplier does not publish an empty weight we say so rather than guess — allow two to three and a half pounds for the bag and check on a scale before you go.

Anything not on this list is too big for Frontier on at least one of the three measurements. We would rather show you a short list that fits than a long one that does not.

The fit guarantee. Every carrier above was measured against what Frontier publishes. If you buy one we said clears this airline and it does not, send it back: we refund it in full and we pay the return shipping.

What we cannot promise is a gate agent’s judgement on the day, or that an airline will not change its published limit after you order. Your pet also has to be able to stand up and turn around inside. What we guarantee is our numbers.

Shop under-seat carriers

Before you book

How to book the pet

Pay in advance during booking.

Minimum age

8 weeks.

Your other bags

The carrier counts as your carry-on. A personal item or a bag costs extra on top.

The most generous footprint published by any airline on this list.

Policies change without notice, and the airline's own page is the authority — not this one. Read the Frontier pet policy, or go back to the full guide covering all nine airlines.

Free, one page

The pre-flight checklist is free, and it is already online

Everything to do in the four weeks before you fly with a pet, in the order you have to do it. Read it now — no email needed. Leave your address and we will send you a 10% code for your first order — plus a warning if your airline moves its published limit before you fly.