Frontier Bag Fees: What a Checked Bag Really Costs

Frontier's official FAQ is direct about this: "Bag prices vary depending on your travel dates and when you purchase them... For the most accurate and up-to-date pricing, please visit our Bag Price Checker." That means the fee for the same size and weight bag can be $20 on one route and $60 on another, and it also changes based on whether you buy it during booking, add it later online, or pay at the airport.

The pattern across ultra-low-cost carriers is consistent: buying your bag during initial booking is always the cheapest option, adding it later through Manage Booking costs more, and paying at the airport counter or gate costs the most. If you know you're checking a bag, add it the moment you book your ticket rather than waiting.

Once you get past the dynamic pricing, the size and weight rules are fixed and published. A standard Frontier checked bag can weigh up to 40 lb and measure up to 62 linear inches, meaning the sum of length, width, and depth. You can check up to 6 bags per trip, per Frontier's official baggage FAQ, though some flights may accept fewer for operational reasons.

Go over those limits and Frontier charges flat, published surcharges rather than a dynamic fee: a bag weighing 41 to 50 lb adds $75 per bag, per direction, and a bag weighing 51 up to 99.99 lb adds $129 per bag, per direction, for bookings made on or after April 4, 2026 (bookings made before that date paid $100 in that heavier tier). Bags over 100 lb are not accepted at all. On the size side, a bag measuring 63 up to 110 linear inches adds a flat $75 per bag, per direction, and Frontier does not accept bags over 110 linear inches under any circumstances.

These overweight and oversize numbers are the one part of Frontier's fee structure that doesn't move with the calendar or the route. A bag that's overweight in July costs the same $75 or $129 surcharge it would cost in December, which is worth knowing if you're trying to budget a trip in advance. The base checked bag fee is the only piece that's genuinely unpredictable.

Frontier's personal item is free on every fare, including its cheapest Basic fare, and can measure up to 18 x 14 x 8 inches and weigh up to 35 lb. This is the one bag every Frontier ticket includes at no charge, so if you're trying to fly Frontier for free, this is the size to pack to.

The carry-on bag is a different story and this is where Frontier flyers get caught out. A full carry-on, up to 24 x 16 x 10 inches (50 linear inches) and up to 35 lb, is free only with Frontier's Economy bundle or higher, or with Elite Silver status and above. On the Basic fare, the carry-on is not included and has to be purchased separately at the same dynamic pricing as a checked bag. This is the core gotcha with Frontier's cheapest tickets: only the personal item is guaranteed free, and both the overhead-bin bag and the checked bag are paid add-ons unless you've booked into a higher bundle.

Add your bag during initial booking, not after. Frontier's own pricing structure rewards buying early and penalizes last-minute additions, and the gap between booking-time pricing and airport pricing can be substantial. If your plans might change, check Frontier's Bag Price Checker for your specific route and dates before you commit, since the same bag can price very differently a week later or on a different route.

If your bag is close to the 40 lb weight cutoff, weigh it at home first. The jump from a standard bag to the 41 to 50 lb overweight tier costs a flat $75, which is often more than the entire base checked bag fee itself, so it's worth removing a few items rather than paying the overweight surcharge. The same logic applies to the 62 linear inch size limit: a bag that's only slightly oversized triggers the same flat oversize fee as one that's dramatically oversized, so there's no partial credit for being close.

Before you buy a new bag for a Frontier trip, run its exact dimensions through the free fit checker on this site to confirm it clears the carry-on or personal item limit you're planning to use, since a bag that's an inch too big at the gate turns into an unplanned fee.

Frontier isn't the only U.S. airline that skips a flat checked bag fee. Allegiant and Avelo both do the same thing, pricing bags dynamically and publishing only the fixed overweight and oversize surcharges. What makes Frontier's carry-on rule notable is that it's stricter about the base fare than some peers: Alaska, for example, still includes a full carry-on on its lowest Saver fare, while Frontier's Basic fare only guarantees the smaller personal item for free.

If you fly Frontier often, it's worth pricing Frontier's Economy bundle against Basic-plus-bags before you assume Basic is cheaper. Once you add a carry-on and a checked bag to a Basic fare at dynamic pricing, the bundle can come out close to even, and the bundle also includes seat selection and other perks Basic doesn't.