Mr. Peanut's Gold Series Standard (Expandable) vs Sherpa Original Deluxe (Medium): which airline pet carrier?
Short answer: Mr. Peanut's Gold Series Standard (Expandable) is within the published size limit of more airlines: 12 of the 58 that publish one, against 11 for the Sherpa Original Deluxe (Medium). In the table, Mr. Peanut's Gold Series Standard (Expandable) is amber for another 14 airlines and the Sherpa Original Deluxe (Medium) for another 28: over the published size, so each would have to be collapsed, flexed or squeezed to go under the seat. Each amber row shows by how much.
Both carriers compared the way an airline sees them: by published size against each airline's under-seat limit. Mr. Peanut's Gold Series Standard (Expandable) is 18 × 11 × 10 in; Sherpa Original Deluxe (Medium) is 17 × 11 × 10.5 in.
Side by side
| Property | Mr. Peanut's Gold Series Standard (Expandable) | Sherpa Original Deluxe (Medium) |
|---|---|---|
| External size (L×W×H) | 18 × 11 × 10 in | 17 × 11 × 10.5 in |
| Type | soft-sided · flexible height · expandable | soft-sided · flexible height |
| Pet weight | up to ~20 lb | up to ~16 lb |
| Airlines it fits outright | 12 of 58 | 11 of 58 |
Airline by airline
Green = within the published size; amber = fits only collapsed / flexed; grey = over. Height is strict — it's the dimension a seat won't negotiate on.
No airlines match.
| Airline | Gold Series Standard (Expandable) | Original Deluxe (Medium) |
|---|---|---|
| Aegean Airlines | Too big | Too big |
| Air Canada | Too big | Flexes — 2.5" over |
| Air Europa | Too big | Too big |
| Air France | Flexes — 0.6" over | Flexes — 1.1" over |
| Air Transat | Too big | Too big |
| airBaltic | Flexes — 0.9" over | Flexes — 1.4" over |
| Alaska Airlines | Too big | Flexes — 1" over |
| Alaska Horizon (Horizon Air) | Too big | Flexes — 1" over |
| Allegiant Air | Exact fit | Fits |
| American Airlines | Exact fit | Exact fit |
| American Eagle (regional, incl. Republic Airways) | Exact fit | Exact fit |
| Asiana Airlines | Too big | Too tall (10.5" > 10.2" soft max) |
| Austrian Airlines | Flexes — 0.9" over | Flexes — 1.4" over |
| Avelo Airlines | Too big | Too big |
| Avianca | Exact fit | Flexes — 0.5" over |
| Azul Linhas Aéreas | Too big | Too big |
| Breeze Airways | Too big | Too big |
| Brussels Airlines | Flexes — 0.9" over | Flexes — 1.4" over |
| Cape Air | Too big | Flexes — 2" over |
| Condor | Flexes — 1" over | Flexes — 1.5" over |
| Contour Airlines | Exact fit | Flexes — 0.5" over |
| Copa Airlines | Exact fit | Exact fit |
| Delta Air Lines | Exact fit | Exact fit |
| Discover Airlines | Flexes — 0.9" over | Flexes — 1.4" over |
| Edelweiss | Flexes — 0.9" over | Flexes — 1.4" over |
| EL AL Israel Airlines | Too big | Too big |
| Etihad Airways | Too big | Too big |
| Eurowings | Flexes — 0.9" over | Flexes — 1.4" over |
| Finnair | Flexes — 2.1" over | Flexes — 2.6" over |
| Frontier Airlines | Exact fit | Fits |
| GOL Linhas Aéreas | Too big | Too big |
| Hawaiian Airlines | Too big | Flexes — 1" over |
| Iberia | Too big | Flexes — 0.7" over |
| ITA Airways | Flexes — 0.9" over | Flexes — 1.4" over |
| JetBlue | Too big | Flexes — 2" over |
| JSX | Too big | Exact fit |
| KLM Royal Dutch Airlines | Flexes — 0.6" over | Flexes — 1.1" over |
| Korean Air | Too big | Too tall (10.5" > 9.8" soft max) |
| LATAM Airlines | Too big | Too big |
| LOT Polish Airlines | Too big | Flexes — 2.6" over |
| Lufthansa | Flexes — 0.9" over | Flexes — 1.4" over |
| Norwegian | Too big | Too big |
| Pegasus Airlines | Fits | Fits |
| Porter Airlines | Fits | Exact fit |
| Royal Air Maroc | Soft-sided not accepted | Soft-sided not accepted |
| SAS Scandinavian Airlines | Too big | Too big |
| Saudia | Fits | Fits |
| Southwest Airlines | Squeezes — 0.5" over | Too big |
| Sun Country Airlines | Too big | Flexes — 1.5" over |
| Swiss International Air Lines | Flexes — 0.9" over | Flexes — 1.4" over |
| TAP Air Portugal | Too big | Flexes — 1.5" over |
| Transavia | Too big | Too big |
| Turkish Airlines | Too big | Too big |
| United Airlines | Exact fit | Exact fit |
| Viva Aerobus | Too big | Flexes — 2.2" over |
| Volaris | Too big | Flexes — 3" over |
| Vueling | Too big | Flexes — 2.2" over |
| WestJet | Too big | Too big |
19 airlines where size doesn't decide it (no pets in the cabin, or no published size)
| Aer Lingus | No cabin pets | No cabin pets |
| Aeroméxico | Size not published | Size not published |
| Air New Zealand | No cabin pets | No cabin pets |
| ANA (All Nippon Airways) | No cabin pets | No cabin pets |
| British Airways | No cabin pets | No cabin pets |
| Cathay Pacific | No cabin pets | No cabin pets |
| China Airlines | No cabin pets | No cabin pets |
| Croatia Airlines | Size not published | Size not published |
| easyJet | No cabin pets | No cabin pets |
| Emirates | No cabin pets | No cabin pets |
| Icelandair | No cabin pets | No cabin pets |
| Japan Airlines | No cabin pets | No cabin pets |
| Mokulele Airlines | Size not published | Size not published |
| Qantas | No cabin pets | No cabin pets |
| Qatar Airways | No cabin pets | No cabin pets |
| Ryanair | No cabin pets | No cabin pets |
| Singapore Airlines | No cabin pets | No cabin pets |
| Southern Airways Express | Size not published | Size not published |
| Virgin Atlantic | No cabin pets | No cabin pets |
Which should you buy?
The Mr. Peanut's Gold Series Standard (Expandable) — it is within the published limit of 12 of the 58 airlines with a published cabin limit, against 11 for the Sherpa Original Deluxe (Medium). That is the whole verdict on airline fit; real under-seat space still varies by aircraft and seat.
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Choose the Mr. Peanut's Gold Series Standard (Expandable) if…
- Flex height plus side expansion: 10" closed, opening to 12". At 18" long it is a big carrier — best on the 11" airlines.
- It clears 12 of 58 airlines with a published cabin limit outright — more than the Sherpa Original Deluxe (Medium).
- Your pet is under ~20 lb.
No new copies on Amazon right nowIn stock and fits the same airlines: Mr. Peanut's Gold Series Mini (Low-Profile) on Amazon →
Choose the Sherpa Original Deluxe (Medium) if…
- Spring-wire top flexes down to squeeze under lower seats. Guaranteed On Board®.
- It clears 11 of 58 airlines with a published cabin limit outright.
- Your pet is under ~16 lb.
Full profiles: Mr. Peanut's Gold Series Standard (Expandable) · Sherpa Original Deluxe (Medium) · best carriers ranked · all carriers
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Common questions
Which fits more airlines, the Mr. Peanut's Gold Series Standard (Expandable) or the Sherpa Original Deluxe (Medium)?
The Mr. Peanut's Gold Series Standard (Expandable) — it's within the published limit of 12 of the 58 airlines with a published cabin limit, against 11 for the other. Real under-seat space still varies by aircraft.
What's the size difference?
Mr. Peanut's Gold Series Standard (Expandable): 18 × 11 × 10 in (up to ~20 lb). Sherpa Original Deluxe (Medium): 17 × 11 × 10.5 in (up to ~16 lb). Height is the strict dimension under a seat, and the Mr. Peanut's Gold Series Standard (Expandable) is the shorter of the two.
Are these figures measured or published?
Published — both sets of dimensions come from the manufacturers' product pages (linked on each carrier's profile), matched against each airline's official carrier limit. We don't invent measurements.