✅ Most under-seat spaces fit 18 × 14 × 8 in bags, but dimensions vary by aircraft.
| Aircraft | Under-Seat (inches) | Notes |
|---|---|---|
| Boeing 737 | ~18 × 14 × 8 | Consistent across U.S. fleets |
| Airbus A320 | ~17 × 13 × 8 | Narrower middle seats |
| Embraer 175 | ~17 × 14 × 8 | Regional jet |
Gotchas
- Window seats may have less height due to box under seat.
- Exit rows sometimes have no under-seat storage.