Allegiant lets a checked bag run to 80 linear inches before it counts as oversize. The industry standard is 62, so Allegiant baggage rules give you 18 inches of size that most airlines charge for.
That is genuinely unusual for an ultra low-cost carrier. The generosity stops at the cabin door.
The carry-on is a paid add-on
A carry-on is not free on most Allegiant fares. It is published at $10 to $75 depending on route and when you buy it.
Bundles that include it exist, and those are worth pricing against the standalone charge. No carry-on weight limit is published.
The bag itself can be 22 by 16 by 10 inches, or 55 by 40 by 25 centimeters. That is larger than the US standard, matching Frontier.
What comes free
One personal item, 18 by 14 by 8 inches, or 45 by 35 by 20 centimeters. Every fare includes it.
Eight inches of depth is generous for an underseat bag. A properly packed backpack fits.
That is the whole free allowance. Everything above it carries a price.
The 80 inch checked allowance in practice
A standard checked bag is 50 pounds and up to 80 linear inches, or 203 centimeters. Most carriers stop at 62 inches.
Past 80 inches, oversize adds $75. That threshold is high enough that most sports equipment and large cases clear it.
If you routinely travel with bulky items, this is the most useful thing in Allegiant baggage rules.
Overweight has three bands
From 51 to 70 pounds adds $50. From 71 to 100 pounds adds $75.
Nothing over 100 pounds is accepted at any price. That is a refusal point rather than a fee.
A 100 pound ceiling is higher than most carriers allow, which fits the pattern of a generous hold and a restricted cabin.
Why there is no fixed fee table
Allegiant prices bags dynamically. The cost varies by route, by bundle and by when you pay.
Booking is cheapest, and the gate is the most expensive place to make the decision. No single fixed checked bag fee is published.
Price your bags during booking, where the figure shown is the one for your itinerary.
How Allegiant baggage rules compare
The unbundled model matches Spirit and Avelo. Personal item free, everything else sold.
Where Allegiant differs is the hold. Its 80 inch size limit and 100 pound ceiling are more generous than either.
Frontier goes the other way, capping standard checked bags at 40 pounds. The two are opposites despite similar fares.
The bottom line
Allegiant baggage rules are tight in the cabin and unusually relaxed in the hold. If you check bulky bags, that trade favors you.
Confirm the current figures in the size checker, and see how we verify what appears here.