Bag allowances differ sharply across low-cost and legacy carriers. Knowing how Spirit aligns with competing budget operators prevents expensive assumptions when booking multi-carrier itineraries.
| Carrier | Personal Item Dimensions | Free Overhead Carry-On? | Typical Gate Bag Penalty |
|---|---|---|---|
| Spirit Airlines | 18 x 14 x 8 inches | No | $79, $99 |
| Frontier Airlines | 18 x 14 x 8 inches | No | $99 |
| Allegiant Air | 18 x 14 x 8 inches | No | $50, $75 |
| Breeze Airways | 17 x 13 x 8 inches | Tier Dependent | $75 |
| United Airlines (Basic) | 17 x 10 x 9 inches | No | $65 + $25 service fee |
Spirit and Frontier share the exact same 18 x 14 x 8 footprint. If you own a bag engineered specifically for one, it functions identically for the other.
