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 … Continue reading What size pet carrier will fit under an airline seat?