Monos Carry-On Pro Plus: 23 x 15 x 9.5 in
carry-on-plus, hardside, 4 spinner wheels, 8.4 lb empty. Exterior figures are the maker's own, wheels and handles included.
Cabin approved at 3 of 19 airlines
The table below shows the verdict at every airline, best fit first, using the same math as the live fit checker. For why so many carry-ons fail the US standard box, see our 22 x 14 x 9 breakdown.
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Does the Carry-On Pro Plus fit? All 19 airlines
23 x 15 x 9.5 in against each airline's published carry-on box, largest side to largest side, sorted best fit first.
| Airline | Cabin max (in) | Verdict | Under seat |
|---|---|---|---|
| Sun Country Airlines | 24 x 16 x 11 | Cabin approved1 in to spare | No |
| Frontier Airlines | 24 x 16 x 10 | Tight squeeze0.5 in to spare | No |
| Southwest Airlines | 24 x 16 x 10 | Tight squeeze0.5 in to spare | not published |
| Alaska Airlines | 22 x 14 x 9 | Gate check1 in over | not published |
| Allegiant Air | 22 x 16 x 10 | Gate check1 in over | No |
| American Airlines | 22 x 14 x 9 | Gate check1 in over | No |
| Avelo Airlines | 22 x 14 x 9 | Gate check1 in over | No |
| British Airways | 22 x 18 x 10 | Gate check1 in over | No |
| Delta Air Lines | 22 x 14 x 9 | Gate check1 in over | not published |
| Hawaiian Airlines | 22 x 14 x 9 | Gate check1 in over | not published |
| JetBlue Airways | 22 x 14 x 9 | Gate check1 in over | No |
| United Airlines | 22 x 14 x 9 | Gate check1 in over | No |
| Air France | 21.7 x 13.8 x 9.9 | Gate check1.3 in over | No |
| Emirates | 21.65 x 14.96 x 8.66 | Gate check1.4 in over | not published |
| Lufthansa | 21.65 x 15.75 x 9.06 | Gate check1.4 in over | No |
| Turkish Airlines | 21.65 x 15.75 x 9.06 | Gate check1.4 in over | No |
| Air Canada | 21.5 x 15.5 x 9 | Gate check1.5 in over | No |
| Ryanair | 21.65 x 15.75 x 7.87 | Gate check1.6 in over | No |
| Qatar Airways | 19.69 x 14.57 x 9.84 | Gate check3.3 in over | not published |
Bag spec source: monos.com · accessed 2026-07-09. Airline limits come from each carrier's official baggage page; open an airline above for its citations. Policies change, so verify a borderline case before you fly.
Monos publishes both imperial (inches) and metric (centimeters) dimensions on every product page, and each hardside suitcase page explicitly states that the listed exterior measurements include the wheels and fixed handles, meaning these are overall, gate sizer style dimensions rather than body only. Monos does not publish a separate body only figure for any line checked, and its two soft sided Metro bags do not carry this wheel inclusion note since they have no wheels.
All 12 Monos bags
