Shape Shifter 37L

Think Tank Shape Shifter 37L is a 33L, 1.76kg3.9lb travel backpack measuring 48.5×31.5×22.6cm19×12.5×9in. It fits the carry-on size limit of 31 of 36 major airlines and the personal-item limit of 0 of 26. Under the seat, its 22.6cm8.9in side is over the 20cm7.9in limit at 15 of the 26 airlines it misses. Specs from thinktankphoto.com, checked September 2026.

Volume: 33Lexpands to 37L
Weight: 1.76kg3.9lb3.9lb1.76kg
Carry-on: 31/36airlines fit it
Personal item: 0/26under-seat limits

Dimensions: 48.5×31.5×22.6cm19×12.5×9in 19×12.5×9in48.5×31.5×22.6cm
Price: $329.75 as of September 2026
Laptop: up to 16"
Opening: n/a
Warranty: Lifetime Covers defects in materials and workmanship, not normal wear, accidents or cosmetic issues.
Compartments: n/a
Bottle pockets: n/a

Price history

$329.75 at every weekly check since Oct 5, 2026 (3 checks).

Checked weekly on the brand's US store.

Organizer
Rain cover
Hip belt (removable)
Sternum strap
Luggage pass-through
Camera compartment

Material: 420D Velocity nylon, 300D diamond weave polyester, 600D polyester

Depth ranges from 10 to 22.6 cm
Divider-free, reconfigurable gear pouches
Front pockets fit a 70-200mm f/2.8

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Last checked: 2026-09. Prices and specs may have changed.

Does the Think Tank Shape Shifter 37L fit airline carry-on limits?

Draw against

Too bigToo big on Ryanair. cabin bag 55×40×20cm21.5×15.5×8in · under the seat 40×30×20cm15.5×12×8in. Bag in cminches, turned to fit.

Flag as a tight fit undercm spare

Airline	Carry-on	Personal item	Cabin-bag weight
Air Arabia	Too bigToo big	Too bigToo big	5.2kg to pack (of 7kg)11.5lb to pack (of 15.4lb)
Air CanadaCabin bag not on every fare	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	No published limitNo published limit
Air FranceCabin bag not on every fare	FitsFits	Too bigToo big	10.2kg to pack (of 12kg shared with personal item)22.5lb to pack (of 26.5lb shared with personal item)
Air India	Too bigToo big	No published limit	5.2kg to pack (of 7kg)11.5lb to pack (of 15.4lb)
AirAsia	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	5.2kg to pack (of 7kg shared with personal item)11.5lb to pack (of 15.4lb shared with personal item)
Alaska Airlines	Tight fit (0.4cm spare)Tight fit (0.2in spare)	No published limit	No published limitNo published limit
Allegiant AirCabin bag not on every fare	FitsFits	Too bigToo big	No published limitNo published limit
American Airlines	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	No published limitNo published limit
ANA (All Nippon Airways)	FitsFits	Too bigToo big	8.2kg to pack (of 10kg shared with personal item)18.1lb to pack (of 22lb shared with personal item)
AviancaCabin bag not on every fare	FitsFits	No published limit	8.2kg to pack (of 10kg)18.1lb to pack (of 22lb)
British Airways	FitsFits	Too bigToo big	No published limitNo published limit
Cebu Pacific	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	8.2kg to pack (of 10kg shared with personal item)18.1lb to pack (of 22lb shared with personal item)
Delta Air Lines	Tight fit (0.4cm spare)Tight fit (0.2in spare)	No published limit	No published limitNo published limit
easyJetCabin bag not on every fare	FitsFits	Too bigToo big	13.2kg to pack (of 15kg)29.1lb to pack (of 33.1lb)
Emirates	Too bigToo big	No published limit	5.2kg to pack (of 7kg)11.5lb to pack (of 15.4lb)
Frontier AirlinesCabin bag not on every fare	FitsFits	Too bigToo big	14.1kg to pack (of 15.9kg)31.1lb to pack (of 35.1lb)
Gol Linhas Aereas	FitsFits	No published limit	8.2kg to pack (of 10kg)18.1lb to pack (of 22lb)
IndiGo	FitsFits	No published limit	5.2kg to pack (of 7kg)11.5lb to pack (of 15.4lb)
JetBlue Airways	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	No published limitNo published limit
KLMCabin bag not on every fare	FitsFits	Too bigToo big	10.2kg to pack (of 12kg shared with personal item)22.5lb to pack (of 26.5lb shared with personal item)
LATAM Airlines	FitsFits	Too bigToo big	10.2kg to pack (of 12kg)22.5lb to pack (of 26.5lb)
LufthansaCabin bag not on every fare	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	6.2kg to pack (of 8kg)13.7lb to pack (of 17.6lb)
Norwegian Air ShuttleCabin bag not on every fare	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	8.2kg to pack (of 10kg shared with personal item)18.1lb to pack (of 22lb shared with personal item)
Qantas	Tight fit (0.4cm spare)Tight fit (0.2in spare)	No published limit	5.2kg to pack (of 7kg shared with personal item)11.5lb to pack (of 15.4lb shared with personal item)
Qatar Airways	Tight fit (1.5cm spare)Tight fit (0.6in spare)	No published limit	5.2kg to pack (of 7kg)11.5lb to pack (of 15.4lb)
RyanairCabin bag not on every fare	Too bigToo big	Too bigToo big	8.2kg to pack (of 10kg)18.1lb to pack (of 22lb)
SAS	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	6.2kg to pack (of 8kg)13.7lb to pack (of 17.6lb)
Singapore Airlines	FitsFits	Too bigToo big	5.2kg to pack (of 7kg)11.5lb to pack (of 15.4lb)
Southwest Airlines	FitsFits	No published limit	No published limitNo published limit
Turkish Airlines	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	6.2kg to pack (of 8kg)13.7lb to pack (of 17.6lb)
United AirlinesCabin bag not on every fare	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	No published limitNo published limit
Vietjet Air	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	5.2kg to pack (of 7kg shared with personal item)11.5lb to pack (of 15.4lb shared with personal item)
VolarisCabin bag not on every fare	FitsFits	Too bigToo big	8.2kg to pack (of 10kg)18.1lb to pack (of 22lb)
VuelingCabin bag not on every fare	Too bigToo big	Too bigToo big	8.2kg to pack (of 10kg)18.1lb to pack (of 22lb)
WestJetCabin bag not on every fare	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	No published limitNo published limit
Wizz AirCabin bag not on every fare	Tight fit (0.4cm spare)Tight fit (0.2in spare)	Too bigToo big	8.2kg to pack (of 10kg)18.1lb to pack (of 22lb)

Compared in any orientation against each airline's published size limit. A tight fit has under 2cm to spare, so a packed soft bag may not pass a sizer. Set it to 0 to turn the warning off. Weight is what the airline allows in the cabin minus this bag's empty 1.76kg3.9lb. Limits and sources. Own a different bag? Check it against every airline.