Duffels

Not sure?

Under the seat or overhead?

Seatmate, 24 L: a gym session plus one change, under the seat. Voyage, 35 L: three days including shoes, in the overhead bin.

Open the 30-second size guide

Size guide

External dimensions, measured with the bag packed.

Size	Dimensions	Capacity	Weight	Trip length
Seatmate 24L Personal item on Spirit, Frontier and American	15.75 × 11.8 × 7.9 in (40 × 30 × 20 cm)	24 L	2.1 lb (0.95 kg)	1–2 days
Atlas Backpack 25–35L Carry-on on every major US airline	18.1 × 11.8 × 5.9 in (46 × 30 × 15 cm)	25–35 L	2 lb (0.9 kg)	2–3 days
Voyage Duffel 35L Carry-on on every major US airline	18.5 × 9.1 × 9.8 in (47 × 23 × 25 cm)	35 L	2 lb (0.9 kg)	3–4 days

Airline limits change without notice — check your carrier before you fly.