Twenty kilograms sounds like plenty — until the check-in scale flashes 21.4 and the agent asks for your card. ⚖️ The 20 kg checked bag is the most common hold allowance in European low-cost flying, yet most travellers still pick the suitcase first and think about the limit second. That is exactly backwards.
In this guide we go through the 10 things that actually decide whether a suitcase up to 20 kg works for you: which airlines still use the 20 kg number in 2026, what dimensions are allowed, how many litres a 20 kg bag really needs, and the detail almost nobody checks — how much of your allowance the empty suitcase eats before you pack a single sock. We finish with a packing method, a checklist and the cases we recommend for this exact job. 👇
🧾 Part 1: The Rules Behind the 20 kg Number
1. 20 kg is a low-cost number — full-service airlines mostly use 23 kg
The first thing to understand is that "20 kg" is not a universal standard. Most full-service European carriers set their Economy checked-bag allowance at 23 kg per piece, and many long-haul fares follow the same rule. The 20 kg figure lives mainly in the low-cost world, where the checked bag is a paid add-on sold in weight tiers.
- Ryanair sells checked bags in 10 kg, 20 kg and 23 kg options, and the 20 kg bag is by far the most popular. You can add up to three 20 kg bags per booking. For the full picture see our Ryanair 20 kg checked baggage guide.
- Wizz Air offers checked bags of 10, 20, 26 or 32 kg, and the WIZZ GO bundle includes one 20 kg bag. Details are in our Wizz Air 20 kg guide.
- easyJet used to sell a standard 20 kg bag but replaced it with a 15 kg and a 23 kg option, with top-ups in 3 kg steps up to 32 kg. If you last flew easyJet a few years ago, your "20 kg habit" is out of date.
The practical lesson: always read the number on your booking, not the one in your head. A bag packed to 22 kg is perfect for a 23 kg fare and an expensive mistake on a 20 kg one.
2. On low-cost airlines the size limit is rarely the problem — the weight is
Here is something that surprises many travellers: the dimension limits for checked bags on the big low-cost carriers are very generous. Ryanair's help centre gives maximum dimensions of 80 × 120 × 120 cm for its 20 kg check-in bag. Wizz Air allows checked bags up to 149 × 119 × 171 cm. easyJet works with a total of 275 cm (length + width + depth) per item.
No normal suitcase comes anywhere near those numbers. In other words, on these airlines you will never be stopped because your 20 kg suitcase is too big — only because it is too heavy. That changes how you should choose the case: size is a question of how you pack, weight is a question of money.
Full-service airlines are different. Most use the 158 cm linear limit (length + width + depth, including wheels and handles) for a standard checked bag. If you fly both low-cost and legacy airlines, 158 cm is the number to design your luggage around. We explain how airlines measure and when they charge in this guide.
3. What one extra kilogram really costs
Low-cost airlines make serious money on excess weight, and the charge is per kilogram, per flight. At the time of writing, excess weight at the airport runs at roughly €13 per kg on Wizz Air, around €11 per kg on Ryanair and about £12 per kg on easyJet. Two kilograms over on a return trip can easily cost more than the bag allowance itself.
Three habits keep you out of that trap:
- Weigh at home with a luggage scale or the bathroom-scale trick (weigh yourself, then yourself holding the bag).
- Leave a 0.5–1 kg buffer. Home scales disagree with airport scales more often than you think, and souvenirs weigh something on the way back.
- Buy weight online, never at the desk. If you know you will be over, upgrading the allowance during booking is almost always cheaper than paying per kilo at check-in. More tactics in our practical guide to avoiding baggage fees.
📏 Part 2: Dimensions and Litres
4. What size is a "20 kg suitcase"?
There is no official "20 kg size" — the weight depends on what you put inside, not on the shell. But experience gives a clear pattern. For a normal holiday or business packing mix (clothes, shoes, toiletries, a few electronics), these are the typical sizes:
- Small check-in (60–65 cm tall, about 40–60 litres): ideal for 4–7 days. Packed normally it will usually weigh 12–17 kg, so you stay well under 20 kg without thinking about it.
- Medium check-in (65–72 cm tall, about 60–75 litres): the sweet spot for a 20 kg allowance. Filled with clothes it lands close to the limit, so it uses the allowance fully without constant overpacking.
- Large check-in (75–82 cm tall, 85–100+ litres): designed for 23 kg fares or bulky, light items such as winter clothing or sports gear. Packed densely, a case this size will go over 20 kg easily.
If you fly mostly on 20 kg allowances, the medium class is the one to buy. A large case is not wrong, but you will spend your trip leaving it half-empty or paying for extra kilos.
5. The 158 cm check: how real cases compare
Even when your low-cost airline allows much more, it pays to own a case that also fits the stricter 158 cm rule used by most full-service carriers — then one suitcase works for every trip. Here is how some cases we stock add up (exterior dimensions, length + width + depth):
- Peli ATX HC25: 66 × 45.7 × 26.9 cm = 138.6 cm — comfortable margin.
- Peli Air 1595: 72.4 × 45.4 × 27.3 cm = 145.1 cm — comfortable margin.
- Peli Air 1615: 82.8 × 46.7 × 28.0 cm = 157.5 cm — right on the limit, by design.
- Peli ATX HC30: 76.2 × 50.8 × 30.7 cm = 157.7 cm — also right on the limit.
Remember that airlines measure everything that sticks out: wheels, feet, handles. A soft suitcase that "grows" when overfilled can fail a size check that a hard case of the same nominal size passes.
6. Litres versus kilograms: why bigger is not better on a 20 kg fare
People often ask how many litres a 20 kg suitcase should have. The honest answer: about 60–75 litres for most packers. Clothing packed normally weighs roughly 0.2–0.3 kg per litre, so a 70-litre interior filled with a typical mix ends up close to the 20 kg line once you add the weight of the case itself.
Go bigger and two things happen. First, the case itself gets heavier. Second, empty space invites packing — the "just in case" jumper, the third pair of shoes, the hair dryer the hotel already has. On a 23 kg or 32 kg fare that is fine; on a 20 kg fare it is how people end up paying €26 for two kilos of things they never used.
If you are packing dense items — books, tools, camera gear, liquids — the calculation flips: 20 kg of equipment can fit in 40 litres. In that case a smaller, well-protected case is the right choice, and the question becomes protection rather than volume.
⚖️ Part 3: The Weight Nobody Checks — The Suitcase Itself
7. The hidden tax: your case's empty weight comes off the 20 kg
This is the single most overlooked factor. The airline weighs the suitcase with its contents. Every kilogram of shell, wheels and handle is a kilogram you cannot pack. Here is what remains of a 20 kg allowance with some common protective cases (empty weights according to the manufacturer):
- Peli Air 1595 (empty): 6.17 kg → 13.8 kg left for your things.
- Peli Air 1615 (empty): 6.4 kg → 13.6 kg left.
- Peli Air 1595TRVL (with travel organizers): 7.3 kg → 12.7 kg left.
- Peli 1560 Protector (empty): 7.71 kg → 12.3 kg left.
- Peli ATX HC25: 8.39 kg → 11.6 kg left.
- Peli ATX HC30: 9.93 kg → about 10 kg left.
Now the uncomfortable truth: a cheap soft-sided or thin polycarbonate suitcase of a similar size often weighs only 3–4.5 kg. So why would anyone choose a heavier case for a 20 kg fare? Because the lightest suitcase is also the one most likely to arrive cracked, soaked or with a torn zip — and then the weight you saved protected nothing. The real goal is not the lightest case, but the lightest case that still protects what is inside. We describe what checked bags go through in what really happens to your suitcase after check-in.
8. Light or armoured: which kind of protective case fits a 20 kg allowance?
Among hard protective cases there are two very different philosophies, and the 20 kg limit makes the choice sharper.
Peli Air cases are built from HPX²™ polymer and designed to be up to 40% lighter than comparable polymer cases, while remaining waterproof (IP67), crushproof and dustproof. For a 20 kg allowance they are the natural choice: the Peli Air 1595 is the mid-size checked case that sits between the carry-on 1535 and the long 1615, with a 56-litre interior and plenty of margin on the 158 cm rule. The Peli Air 1615 gives you the maximum length allowed on most airlines — useful for tripods, light stands or longer gear — at only 6.4 kg empty.
Peli ATX cases (HC25, HC30) take the opposite route: a sealed, zipper-free polypropylene shell with Peli Armor™ construction, TSA locking latches and Hinomoto® spinner wheels. They are the "real suitcase" option — a removable liner with compression, four wheels, a classic travel look — and they are heavier because of it. On a 23 kg or 32 kg fare that extra weight is irrelevant; on a 20 kg fare the HC25 is the sensible size, while the HC30 is best kept for trips where you buy a higher allowance.
A simple rule: if every kilogram counts, choose Air; if you want a four-wheel travel suitcase that simply refuses to break, choose ATX and size it to the allowance.
🧳 Checked cases that make the most of a 20 kg allowance
🎒 Part 4: Packing to Exactly 20 kg
9. A packing method that lands under the scale every time
Packing to a weight limit is a different skill from packing to a size limit. These steps work for a week-long trip and scale up or down easily:
- Start with the empty weight. Put the empty case on the scale and write the number down. That is your starting point, not zero.
- Pack heavy items first, low and near the wheels. Shoes, toiletry bag, chargers and books go at the wheel end. The case stands and rolls better, and nothing heavy crushes your clothes.
- Roll soft clothes and use packing cubes. Rolling reduces creasing and makes gaps visible; cubes stop the load from shifting and make a mid-trip repack quick.
- Use the dead space. Socks and cables inside shoes, small items in the lid pocket or lid organizer, fragile items wrapped in clothing in the middle of the case.
- Weigh at the halfway point, then again at the end. Checking halfway prevents the "unpack everything" moment at 11 p.m.
- Keep the heavy-but-small items in your cabin bag. A power bank, camera, laptop and chargers can easily weigh 3–4 kg. They should travel in the cabin anyway (spare lithium batteries are not allowed in checked baggage), which frees up checked allowance. For the cabin side of the trip, see our guides on packing a suitcase under 10 kg and fitting a week into carry-on luggage.
- Leave room for the way back. Pack to about 18.5–19 kg on the outbound flight. Food, wine and souvenirs have a way of turning a 19 kg bag into a 21 kg bag.
10. Protect what matters: what not to put in a 20 kg checked bag
A checked bag goes on conveyor belts, gets stacked under heavier bags, and waits on the apron in the rain. That is why some things should never go into it — no matter how much allowance is left:
- Spare lithium batteries and power banks — prohibited in checked baggage, cabin only.
- Laptops, cameras, lenses and drones — technically allowed in many cases, but high-value electronics are safest with you. If equipment must go in the hold, use a hard, waterproof case with a fitted interior, not a soft suitcase.
- Medication, documents, keys and valuables — if the bag is delayed, you need these on day one.
- Anything you cannot replace — the classic rule of checked baggage.
What you do check in should sit in a case that shrugs off rough handling and rain: a sealed, waterproof shell with a pressure equalization valve and a lock you trust. That, more than the brand on the label, decides whether your 20 kg arrive in the same condition they left.
And because most 20 kg trips also involve a cabin bag, here are the carry-on cases that pair best with the checked cases above: 👇
✈️ Cabin companions for your 20 kg checked bag
✅ Checklist: Your 20 kg Suitcase Before Every Flight
- ☐ Checked the allowance on the booking: 20 kg, 23 kg or something else?
- ☐ Checked the size rule: low-cost limits or the 158 cm linear limit?
- ☐ Weighed the empty case and subtracted it from the allowance.
- ☐ Chose the right size: medium (about 60–75 litres) for a 20 kg fare.
- ☐ Heavy items low, near the wheels; soft items rolled or in cubes.
- ☐ Weighed halfway and at the end, with a 0.5–1 kg buffer.
- ☐ Batteries, power banks, laptop, camera, medication and documents in the cabin bag.
- ☐ Room left for the return trip (packed to about 18.5–19 kg).
- ☐ If you will be over: extra weight bought online, not at the desk.
❓ Frequently Asked Questions
What are the dimensions of a 20 kg suitcase?
There is no fixed size. For typical packing, a medium check-in case about 65–72 cm tall with 60–75 litres of capacity reaches roughly 20 kg when full. Ryanair allows checked bags up to 80 × 120 × 120 cm and Wizz Air up to 149 × 119 × 171 cm, so on those airlines weight is the real limit. Full-service airlines usually use the 158 cm linear limit.
How many litres is a 20 kg suitcase?
For clothes and a normal travel mix, about 60–75 litres. Dense items such as tools, books or camera gear can reach 20 kg in 40 litres or less.
Does the weight of the suitcase count towards the 20 kg?
Yes. The airline weighs the bag with its contents, so a case weighing 6 kg empty leaves you 14 kg for your things.
Which airlines still use a 20 kg checked bag?
At the time of writing, Ryanair (10, 20 and 23 kg options) and Wizz Air (10, 20, 26 and 32 kg) both sell 20 kg bags. easyJet replaced its 20 kg bag with 15 kg and 23 kg options. Most full-service carriers use 23 kg in Economy. Always check your own booking.
What happens if my suitcase weighs 21 kg?
You pay an excess weight fee at the airport, charged per kilogram and per flight — roughly €11–13 per kg on the big low-cost carriers. Moving items to your cabin bag or buying extra weight online is almost always cheaper.
Is a hard case worth it for a 20 kg allowance?
If what you pack matters to you, yes — as long as you choose a light one. A case such as the Peli Air 1595 weighs just over 6 kg empty and is waterproof and crushproof, which is a fair trade for the peace of mind on the baggage belt.
🏁 The Bottom Line
A suitcase up to 20 kg is not about finding the biggest bag the airline allows — on low-cost carriers that limit is so generous it hardly matters. It is about three numbers: the allowance on your booking, the empty weight of your case, and the litres you actually need. Get those right and the check-in scale becomes a formality instead of a gamble.
Choose a medium case of about 60–75 litres, keep its empty weight as low as the protection you need allows, pack heavy items low and in the cabin, and leave a kilogram for the way home. Do that, and your 20 kg will arrive exactly as you packed them — dry, intact and paid for once. 🧳✈️
