The Short Answer
Most airlines allow you to bring two bags on board: one larger carry-on that goes in the overhead bin, and one smaller personal item that goes under the seat in front of you. Both are usually included in your ticket price — but the rules vary significantly by airline.
What Counts as a Carry-On?
A carry-on is your main cabin bag — typically a rolling suitcase, large backpack, or duffel that fits in the overhead compartment. Most major airlines allow one carry-on plus one personal item at no extra charge.
Standard carry-on size limits hover around 22 × 14 × 9 inches (56 × 36 × 23 cm), but this varies. Always check your specific airline before flying.
What Counts as a Personal Item?
A personal item is your smaller secondary bag — a purse, laptop bag, small backpack, or tote that fits under the seat in front of you. Typical size limits are around 18 × 14 × 8 inches (45 × 35 × 20 cm).
Common personal items that work for most airlines:
- Purse or handbag
- Laptop bag or briefcase
- Small backpack (under 25L)
- Tote bag
- Diaper bag (often exempt from size rules)
Size Limits by Airline
| Airline | Carry-On Max Size | Personal Item Max Size | Fee? |
|---|---|---|---|
| Delta | 22 × 14 × 9 in | 18 × 14 × 8 in | No fee (most fares) |
| United | 22 × 14 × 9 in | 17 × 10 × 9 in | No fee (most fares) |
| American | 22 × 14 × 9 in | 18 × 14 × 8 in | No fee (most fares) |
| Southwest | 24 × 16 × 10 in | 18.5 × 8.5 × 13.5 in | No fee |
| Spirit | 22 × 18 × 10 in | 18 × 14 × 8 in | Carry-on: $49–$79 |
| Frontier | 24 × 16 × 10 in | 18 × 14 × 8 in | Carry-on: $35–$50 |
| Ryanair | 55 × 40 × 20 cm | 40 × 20 × 25 cm | Carry-on: €6–€29 |
| Korean Air | 55 × 40 × 20 cm | No separate limit | No fee |
What Fits in a Personal Item?
More than you'd think — if you pack smart. A 20–25L backpack used as a personal item can carry:
- Laptop + charger
- Change of clothes for 1–2 days
- Toiletry bag (TSA-compliant)
- Snacks, book, headphones
- Travel documents and wallet
For short trips (1–3 days), many travelers skip the carry-on entirely and just use a personal item to save money on budget airlines.
Tips to Avoid Extra Fees
- Check your fare type — basic economy often excludes overhead carry-ons even on major airlines.
- Wear your heaviest items — coat, boots, and thick sweaters don't count toward bag limits.
- Prepay online if you need a carry-on — buying at the gate is always more expensive.
- Use a personal item backpack — a well-packed 20L backpack under the seat beats a rolling carry-on that gets gate-checked.