Compare Frontier Airlines and Allegiant Air for the same passenger, route, ticket date and measured bag. The key policy difference is explained below; either live itinerary quote can still change the result.
What we could confirm
| Field | Frontier Airlines | Allegiant Air |
|---|---|---|
| What we know | Official sources disagree | Some rules checked |
| Standard weight | 40 lb | 50 lb |
| Standard outside size | 62 linear in | 80 linear in |
Compare the same purchase conditions
The Frontier Airlines and Allegiant Air details above may cover different fares or routes. Check who flies each leg and what each ticket includes before you compare a bag charge.
What changes between these airlines
Both airlines distinguish the underseat personal item from a separately priced carry-on. Frontier publishes a 40 lb standard checked threshold; Allegiant lists a different checked-bag product. Compare the packed item’s three outside dimensions before comparing price.
| Airline | When it applies | Standard bag limit | Published fee example |
|---|---|---|---|
| Frontier Airlines | Standard 40 lb allowance, with bundle/status overrides and variable base prices. | 40 lb; 62 linear in | 41–50 lb: $75 overweight surcharge. |
| Allegiant Air | Allegiant ordinary baggage; route and purchase channel determine prices. | 50 lb; 80 linear in | No single base fee imported. Standard checked dimensions allow 80 linear inches, not a generic 62. |
The examples above may use different routes, fares, or dates. Don’t subtract one from the other as if they were quotes for the same flight. Use the interactive comparison for your own bag, then open both airlines’ booking flows for the final charge.
Compare your own trip
- Find the fare on each ticket and the airline flying each leg.
- Compare the same bag number, weight, and outside size for the same traveler and direction.
- Keep taxes, currency, and purchase timing in view. If either airline needs a booking quote, you don’t have a reliable price difference yet.
Check your bag dimensions · Compare fare plus baggage
Official sources and evidence
- Frontier Airlines: Bag size and weight limits (official search excerpt; checked 2026-10-31)
- Frontier Airlines: Bag options (official page read; checked 2026-10-31)
- Allegiant Air: Carry-on and checked baggage (official page read; checked 2026-10-31)