Does the Mr. Peanut's Gold Series Standard (Expandable) fit Southwest Airlines?
Close — the Mr. Peanut's Gold Series Standard (Expandable) (18 × 11 × 10 in) is over Southwest Airlines's 18 × 10.5 × 10 in limit on paper, but flexes down — measure yours before you fly.
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18 × 11 × 10 in is 0.5" over on width against a 18 × 10.5 × 10 in limit, and height clears with 0" to spare. Soft sides compress, so this usually goes under the seat — but it is over the published figure, so measure yours and be ready for an agent to check.
Last verified 2026-09-24 · matched to the published Southwest Airlines limit. Every fit is against the published maximum; real under-seat space varies by aircraft (why).
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