Short answer: plain packing cubes do not save space. Compression cubes do. Most of the disappointment around packing cubes comes from buying the first kind while expecting the second.
Here is what each one actually does, from someone who sells them and would rather you buy the right thing than return the wrong one.
What plain packing cubes do
A standard packing cube is a fabric box with a zip. You put clothes in, you zip it, you place it in the suitcase.
It does not reduce the volume of your clothes. If anything, the fabric and zip add a few millimetres. Anyone claiming plain cubes create space is selling you something.
What they do instead:
- They hold the arrangement. The neat pack you did at home survives being thrown into a hold and dragged across a city. Loose clothes do not.
- They make unpacking a two-second job. Lift three cubes into a hotel drawer, done. Lift them back on departure, done.
- They stop the archaeology. No digging to the bottom of the case for one shirt and wrecking everything above it.
- They make the case squarer. Loose clothes leave odd voids. Cubes stack, and stacked shapes waste less.
That last point is where the confusion starts. Cubes do let you use your space more efficiently — fewer awkward gaps. But the clothes themselves take up exactly what they took up before.
What compression cubes do differently
A compression cube has a second zipper. You fill the cube, close the main zip, then run the second zip around — it pulls the sides inward and forces air out of the fabric.
This genuinely reduces volume, because most of what a pile of clothes occupies is air between the layers. Knitwear, T-shirts, fleece and anything fluffy compress well. Denim and structured items barely compress at all — they have little trapped air to remove.
Two things nobody mentions in the marketing:
Compression does not reduce weight
Not by a gram. If your airline enforces a weight limit rather than a size limit — and many budget carriers enforce both — compression will not help you. Check which limit is binding before you count on it.
Compression cubes are harder on zips
The compression zip is under real tension every time you use it, which is why it is the part that fails on cheap sets. If you overfill the cube and force the zip, you will break it. Pack to comfortably full, then compress.
So which should you buy?
| Your situation | What to get |
|---|---|
| You check a bag and have space to spare, but hate the mess | Plain cubes are enough |
| You travel carry-on only and fight the size limit | Compression cubes |
| You pack bulky knitwear, hoodies, winter layers | Compression cubes — this is where they shine |
| You pack mostly shirts, suits, structured items | Plain cubes. Compression creases what you want flat |
| Your airline limit is weight, not size | Neither will help. Pack less |
| You take one short trip a year | Honestly, skip it. A tote bag inside the case does most of the job |
How much space do compression cubes actually save?
You will see claims from 30% to 60%. Both can be true, and both can be meaningless, because it depends entirely on what you compress.
A cube of fleece and knitwear will compress dramatically — that is mostly air. The same cube filled with jeans and a pair of trainers will barely move. Any brand quoting a single percentage is quoting their best case with their fluffiest test load.
The useful way to think about it: compression buys back roughly the space of one to two days of clothing on a week-long trip. That is often the difference between closing the carry-on and not. It is not the difference between one bag and two.
How many cubes do you need?
Three is the number that keeps coming up, and it is not arbitrary — it maps onto how people actually sort clothes:
- Large — tops and outer layers
- Medium — trousers, shorts, heavier items
- Small — underwear, socks, chargers, small essentials
Six-piece sets look like better value, and for a family they are. For one person they usually mean three cubes in the case and three in a drawer at home.
If two people are travelling, a set each in different colors beats one big set shared — nobody has to open three cubes to find their own shirt.
The verdict
Plain cubes are an organization tool. Compression cubes are an organization tool that also buys back a little volume. Neither is magic, and neither fixes overpacking — the biggest space saving available to anyone is still leaving two items at home.
But if you travel more than a couple of times a year, the daily benefit is not really about space at all. It is that unpacking takes seconds and your bag looks the same on day six as it did on day one.
PACKYRA makes a three-piece compression packing cube set — large, medium and small, with a compression zipper on each. See the set.