The personal-item volume ceiling: how many litres each airline actually allows (2026)

Short answer: every airline that publishes a personal-item size allows a rectangular box of 18 to 35 litres. A 25 × 17 × 14 cm bag holds about 6 litres, so volume is never what stops you at the gate — depth is. The strictest allowance (Lufthansa, SWISS, Air France, KLM, British Airways, Iberia, Condor at 40 × 30 × 15 cm) is still three times our bag's volume.

What the allowance really measures

An airline's personal-item limit is a box, not a bag. Multiply the three published numbers and you get the maximum rectangular volume it will accept "under the seat in front of you." We did that for every carrier that publishes a hard size.

Airline	Published limit	Allowance volume	Type
Southwest	18.5 × 8.5 × 13.5 in	34.8 L	US
American	18 × 14 × 8 in	33 L	US
Spirit	18 × 14 × 8 in	33 L	US
Eurowings	40 × 30 × 25 cm	30 L	low-cost
United	9 × 10 × 17 in	25.1 L	US
Ryanair	40 × 30 × 20 cm	24 L	low-cost
easyJet	40 × 30 × 20 cm	24 L	low-cost
Transavia	40 × 30 × 20 cm	24 L	low-cost
Vueling	40 × 30 × 20 cm	24 L	low-cost
Wizz Air	40 × 30 × 20 cm	24 L	low-cost
Lufthansa	40 × 30 × 15 cm	18 L	legacy
SWISS	40 × 30 × 15 cm	18 L	legacy
Air France	40 × 30 × 15 cm	18 L	legacy
KLM	40 × 30 × 15 cm	18 L	legacy
British Airways	40 × 30 × 15 cm	18 L	legacy
Iberia	40 × 30 × 15 cm	18 L	legacy
Condor	40 × 30 × 15 cm	18 L	legacy

The surprise is how little volume varies

The spread runs from 18.0 L (the seven European legacy carriers at 40 × 30 × 15 cm) to 34.8 L (Southwest). That looks like a two-fold difference — until you put a real bag next to it. Our 25 × 17 × 14 cm bag is 5.95 L on the outside. Even the strictest allowance holds three of them. Volume has never been the constraint on a personal item; the third dimension has.

Why this matters for a 25 × 17 × 14 cm bag

Because the smallest allowance is 18 L and the bag is 6 L, you could in theory pack three times the bag's volume and still be "within the box" on the strictest carrier. The reason travellers get stopped is not volume — it is that a soft bag grows in depth as you fill it, and depth is capped at 15 cm on six carriers. See the depth distribution for where that wall sits.

Three carriers publish no box at all

Delta, ANA and JAL do not state a personal-item volume. They ask only that it fit under the seat. There is no litre figure to clear, which makes a 6 L bag safe by definition — but also means the gate, not a number, decides.

The number to remember is not litres. It is 15 cm.

Should you buy the Jelkin 25 for this?

Volume has never been what stops a personal item — depth is. The Jelkin 25 is 5.95 L on the outside, one third of the strictest allowance any carrier publishes, so if your problem is "I cannot fit everything in," this is the wrong bag. If your problem is "I got stopped at the gate and charged," it is the right one. Buy it for the sizer, not for the litres.

How to check this yourself before you fly

1. Lay the bag flat and measure all three edges with a tape — not by eye. Guessing is how people end up at the sizer with a bag they believed was fine.
2. Measure depth first. It is the axis every carrier caps hardest, and the only one with a real wall at 15 cm.
3. Compare against the row for the carrier you are actually flying, not the average. The spread runs from 18 L to 34.8 L.
4. Measure again once the bag is packed. A soft bag gains 1–2 cm in depth as it fills, which is exactly how a "compliant" bag becomes a gate fee.

Keep reading:

• airline personal item size checker — all 19 carriers side by side
• one-centimetre depth cliff — why 15 cm decides six airlines
• the 25 cm bag that fits every sizer — length-vs-depth end to end
• why external dimensions lie about capacity — how we measure bags
• Jelkin 25 — the 25 × 17 × 14 cm bag measured on this page