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Best free personal item size for US airlines

The under-seat personal item that’s free on every US airline — including Spirit and Frontier.

Best personal item size
41 × 33 × 18 cm
16.1 × 13 × 7.1 in
largest × middle × shortest side

Fits the personal item allowance on all 6 airlines in this group. The tightest is Allegiant Air.

Bags that fit

tomtoc
Voyage Under-Seat Backpack 20L
Tight — risky
39 × 24 × 18 cm
20 L
0.7 kg
0 cm to spare
from £60View →
Gonex
Foldable Daypack 20L
Fits
39 × 28 × 15 cm
20 L
0.3 kg
2 cm to spare
from £20
Fjällräven
Kånken 16L
Fits
38 × 27 × 13 cm
16 L
0.5 kg
3 cm to spare
from £85View →

personal item limit per airline (6)

AirlineLimitWeight
Allegiant Air41 × 38 × 18 cm
Breeze Airways43 × 33 × 20 cm
Avelo Airlines43 × 33 × 22 cm
Sun Country43 × 33 × 23 cm
Spirit Airlines46 × 36 × 20 cm
Frontier Airlines46 × 36 × 20 cm

FAQ

What is the best personal item size for this group?+

A bag no larger than 41 × 33 × 18 cm (16.1 × 13 × 7.1 in) fits the personal item allowance on all 6 airlines in this group — the limit is set by Allegiant Air.

Why not just buy the biggest bag?+

Because the strictest airline in the group wins. A bag that fits Allegiant Air fits everyone here; a larger one would be rejected or charged there. Buy for the tightest limit and you’re safe on all.

Should I leave a safety margin?+

Yes — measure with wheels and handles, and pick a bag a touch under the limit. A packed bag bulges, and low-cost airlines measure strictly at the gate.

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