Luggage Size & Cabin Bag Checker
Enter the outer length, width and height of a suitcase and its packed weight to get the linear total, the usable capacity, and whether it fits the cabin or has to be checked.
A suitcase is sold by the inch, but it is accepted by the centimetre. Two 20-inch cases can differ by five centimetres on the outside, and one flies in the cabin while the other is sent to the hold. Enter the real outer size, wheels and handles included, and the packed weight; the page returns the linear total, the usable capacity and a clear cabin-or-checked verdict.
Your suitcase
Measure the outside, wheels and handles included. Weigh it packed, not empty.
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Common suitcase sizes
| Nominal size | Typical outer size (cm) | Linear | Net litres | Trip length | Cabin |
|---|---|---|---|---|---|
| 16″ | 43 × 30 × 18 | 91 cm | 18 L | 1–2 days | Usually — check depth |
| 18″ | 46 × 32 × 20 | 98 cm | 22 L | 2–3 days | Usually — check depth |
| 20″ | 55 × 35 × 23 | 113 cm | 38 L | 3–5 days | Usually — check depth |
| 22″ | 58 × 38 × 24 | 120 cm | 44 L | 5–7 days | Checked only |
| 24″ | 65 × 42 × 26 | 133 cm | 58 L | 7–10 days | Checked only |
| 26″ | 70 × 45 × 28 | 143 cm | 72 L | 10–12 days | Checked only |
| 28″ | 75 × 48 × 30 | 153 cm | 88 L | 12–14 days | Checked only |
| 30″ | 80 × 52 × 32 | 164 cm | 108 L | 15 days + / moving | Check with airline |
| 32″ | 85 × 55 × 35 | 175 cm | 124 L | Moving, study abroad | Check with airline |
How the rule actually works
- Measure the outer shell, not the packing space. Wheels, handles and expansion zips all count at the gate.
- The linear total is the hard limit: 55 + 40 + 20 = 115 cm. A typical 20-inch case sits at about 113 cm, so the margin is only 2 cm.
- Soft bags can be squeezed by 1–2 cm; hard shells cannot. Low-cost carriers use a metal sizer, and if it does not drop in, it does not fly.
- Checked baggage is limited by linear total (usually 158 cm) and by weight (23 kg economy, 32 kg business), and both must pass.
- Anything over 158 cm is oversized: it needs airline approval, and bags over 32 kg are refused in many countries for manual-handling reasons.
Before you buy
- Check the internal dimensions too. Wheels and the handle housing take 3–5 cm, so the usable depth is smaller than the outside suggests.
- A 20-inch cabin case holds roughly 35–40 litres, which is 3–5 days of clothing if you pack around laundry.
- Cost the cabin bag into the ticket: a low-cost fare with a paid cabin bag can still beat a full-service fare, but only if the bag actually fits.
- For a 28-inch case or larger, check the lift, the stair turn and the door width at your destination before you buy.
Four common mistakes
- Treating a 24-inch case as a cabin bag. Its linear total is about 133 cm, well over the 115 cm limit.
- Trusting the inch label alone. Different brands vary by up to 5 cm at the same nominal size.
- Forgetting the empty weight. A 3.5 kg case leaves only 3.5 kg of belongings under a 7 kg cabin limit.
- Reading 158 cm as a per-side limit. It is the sum of the three sides, and it applies to checked bags, not cabin bags.
Allowances differ by airline, route and fare class. Treat the result as a planning check and confirm the current rules on your carrier’s website before you travel.