Sizeproof
Thule · carry-on

Does the Thule Aion Travel Backpack 40L fit as a carry-on?

By its listed size it fits 22 of 38 airlines that publish a carry-on limit, is borderline on 11 and is too big for 5.

Size and specs

Listed size52 × 33 × 23 cm (20.5 × 13 × 9.1 in)
Volume40 L
Empty weight3.3 lb (1.5 kg)
Laptop sleeveup to 17 in
Wheelsnone
List price$209.95 (seen 2026-10-19)
The brand doesn't say whether this is the outside size.

Against the usual US limit

05101520in FrontSide

Dashed and yellow: American Airlines' carry-on limit, 22 × 14 × 9 in. Coloured: this bag's listed size.

Every airline

Airlinecarry-on limitThis bag
United States
Alaska Airlines22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Allegiant Air10 × 16 × 22 in (25 × 41 × 56 cm)Fits 0.9 in to spare
American Airlines22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Avelo Airlines22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Breeze Airways22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Delta Air Lines22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Frontier Airlines24 × 16 × 10 in (61 × 41 × 25 cm)Fits 0.9 in to spare
Hawaiian Airlines22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
JetBlue22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Southwest Airlines24 × 16 × 10 in (61 × 41 × 25 cm)Fits 0.9 in to spare
Sun Country Airlines24 × 16 × 11 in (61 × 41 × 28 cm)Fits 1.9 in to spare
United Airlines9 × 14 × 22 in (23 × 36 × 56 cm)Borderline 0.1 in over, too deep
Canada & Mexico
Aeromexico55 × 40 × 25 cm (21.7 × 15.7 × 9.8 in)Fits 0.8 in to spare
Air Canada9 × 15.5 × 21.5 in (23 × 39 × 55 cm)Borderline 0.1 in over, too deep
Porter Airlines21.5 × 15.5 × 9 in (55 × 39 × 23 cm)Borderline 0.1 in over, too deep
Viva Aerobus22 × 16 × 10 in (56 × 41 × 25 cm)Fits 0.9 in to spare
Volaris55 × 40 × 25 cm (21.7 × 15.7 × 9.8 in)Fits 0.8 in to spare
WestJet22 × 14 × 9 in (56 × 36 × 23 cm)Borderline 0.1 in over, too deep
Latin America
Avianca55 × 35 × 25 cm (21.7 × 13.8 × 9.8 in)Fits 0.8 in to spare
Copa Airlines56 × 36 × 26 cm (22 × 14.2 × 10.2 in)Fits 1.2 in to spare
LATAM Airlines55 × 35 × 25 cm (21.7 × 13.8 × 9.8 in)Fits 0.8 in to spare
Europe
Aer Lingus55 × 40 × 24 cm (21.7 × 15.7 × 9.4 in)Fits 0.4 in to spare
Air France55 × 35 × 25 cm (21.7 × 13.8 × 9.8 in)Fits 0.8 in to spare
British Airways56 × 45 × 25 cm (22 × 17.7 × 9.8 in)Fits 0.8 in to spare
easyJet56 × 45 × 25 cm (22 × 17.7 × 9.8 in)Fits 0.8 in to spare
Iberia56 × 40 × 25 cm (22 × 15.7 × 9.8 in)Fits 0.8 in to spare
Icelandair55 × 40 × 20 cm (21.7 × 15.7 × 7.9 in)Too big 1.2 in over, too deep
KLM55 × 35 × 25 cm (21.7 × 13.8 × 9.8 in)Fits 0.8 in to spare
Lufthansa55 × 40 × 23 cm (21.7 × 15.7 × 9.1 in)Fits right at the limit
Ryanair55 × 40 × 20 cm (21.7 × 15.7 × 7.9 in)Too big 1.2 in over, too deep
Turkish Airlines23 × 40 × 55 cm (9.1 × 15.7 × 21.7 in)Fits right at the limit
Virgin Atlantic23 × 36 × 56 cm (9.1 × 14.2 × 22 in)Fits right at the limit
Vueling55 × 40 × 20 cm (21.7 × 15.7 × 7.9 in)Too big 1.2 in over, too deep
Wizz Air55 × 40 × 23 cm (21.7 × 15.7 × 9.1 in)Fits right at the limit
Middle East & Asia-Pacific
Emirates55 × 38 × 22 cm (21.7 × 15 × 8.7 in)Too big 0.4 in over, too deep
Japan Airlines55 × 40 × 25 cm (21.7 × 15.7 × 9.8 in)Fits 0.8 in to spare
Qantas56 × 36 × 23 cm (22 × 14.2 × 9.1 in)Fits right at the limit
Qatar Airways50 × 37 × 25 cm (19.7 × 14.6 × 9.8 in)Too big 0.8 in over, too tall

"Borderline" means over by no more than the rounding in published sizes (0.5 cm, about 0.2 in). It may pass at the gate, but we don't promise it.

Where these numbers come from

Notes from our data check

thule.com blocks plain requests (403), so it was read with a page-fetch tool (numbers came via a summariser, not raw HTML). US page: 'Dimensions 13 x 9.1 x 20.5 in', 'Weight 3.2 lb', 'Volume 40 L', 'Padded storage protects up to a 17" laptop', 'Compliant with most airlines carry on requirements', $209.95. UK page: 'Dimensions 33 x 23 x 52 cm', 'Weight 1.5 kg'. The in and cm figures agree (20.5 in = 52.1 cm). Model 3204723. Reordered to [H, W, D]. CONFLICT: REI (search extract) lists a 16" laptop compartment; MEC lists 47 x 28 x 23 cm and a 15" laptop; Amazon lists 1.45 kg. Brand used. Amazon B09NL7ZVCD (model 3204723) in stock, 4.3 stars from 777 ratings, #70 in Casual Daypack Backpacks.