The size of a pet carrier that fits under an airline seat varies by airline, but the general dimensions are:
- Soft-sided carriers: 17″ L × 11″ W × 9.5″ H (43 cm × 28 cm × 24 cm)
- Some airlines allow slightly larger soft-sided carriers since they can compress to fit.
- Hard-sided carriers: 16″ L × 10″ W × 8.5″ H (41 cm × 25 cm × 22 cm)
- Hard-sided carriers have stricter size limits because they don’t flex.

Examples of Airlines’ Pet Carrier Size Limits:
✔ American Airlines: 18″ × 11″ × 11″ (soft-sided)
✔ Delta Airlines: 18″ × 11″ × 11″
✔ United Airlines: 17.5″ × 12″ × 7.5″
✔ Southwest Airlines: 18.5″ × 13.5″ × 9.5″
✔ JetBlue: 17″ × 12.5″ × 8.5″
For maximum comfort and compliance, the Ibiyaya 6in1 JetPaw TSA-Approved Expandable Pet Carrier and Panorama Ziffer-Free Small Travel Carrier are great option, as it meets airline requirements while providing extra space when expanded. It is also multi-functional that it can be use as backpack, frontpack, pet car seat carrier, pet handbag, and a regular pet stroller with detachable carrier.
Would you like help finding a carrier for a specific airline or pet size?