How to choose a mattress for your new bed
Your mattress is the same size as your bed. Pick firmness by sleeping position and weight: softer if you sleep on your side, firmer if on your back.
In short: The mattress is exactly the size of the bed: a 160×200 cm bed takes a 160×200 cm mattress. Choose firmness by the position you sleep in most and by your weight: side sleepers usually feel better on a softer mattress that lets the shoulder and hip sink in a little; back sleepers, and anyone who doesn't like sinking in, usually prefer something firmer. Give it up to three weeks before you decide — that's how long your body needs to get used to it.
You buy a bed once in many years, and the mattress is the part of it you're actually in contact with. The choice comes down to a few simple questions: what size is the bed, how do you sleep, what do you weigh, and how much do you care about airflow and a washable cover.
Size: the same as the bed
No compromise here. Bed sizes are given by the mattress they take, so a 140×200 cm bed takes a 140×200 cm mattress. The standard sizes are 90×200, 120×200, 140×200, 160×200, 180×200 and 200×200 cm. If you haven't settled on the bed yet, our guide to double bed sizes helps you choose between 140, 160, 180 and 200.
There's one more measurement people forget: thickness. The mattress sits partly inside the frame, between the side rails, and rises above them. Massif side rails are 12 cm as standard (15 cm as an option), and our mattresses are 23 and 25 cm thick. The thicker the mattress, the higher you sit and the less of the headboard stays visible. For more on sitting height, see how high a bed should be.
Firmness and how you sleep
Firmness is usually described on a four-step scale: soft → medium-soft → medium-firm → firm. There's no "correct" firmness for everyone. What matters is the position you spend most of the night in.
| How you usually sleep | What to look for | Rough firmness |
|---|---|---|
| On your side | lets the shoulder and hip sink in a little, so you don't feel pressure there | soft – medium-soft |
| On your back | an even surface you don't sink into | medium-firm – firm |
| On your front | keeps the hips from dropping lower than the rest of you | medium-firm – firm |
| You change position a lot | easy to turn over, without climbing out of a dip | medium |
Treat the table as a starting point. If you've slept well for years on a particular mattress, its firmness tells you more than any chart.
Your weight changes how firm it feels
The same mattress feels firmer to a lighter person and softer to a heavier one, because a heavier body presses further into the comfort layers. That's why every mattress has a recommended weight. If you're close to or above it, go for the firmer option or the one with the higher limit. Our SpringHero is recommended up to 120 kg and FoamHero up to 140 kg.
Pocket springs, foam or latex
What's inside decides how the mattress moves under you and how much air flows through it.
| Construction | How it feels | Strengths | Worth knowing |
|---|---|---|---|
| Pocket springs | springy, responsive | each spring has its own pocket and works independently, so you feel your partner's movement less; plenty of air between springs | heavier; quality also depends on the layers above the springs |
| Foam | even, no springs | consistent surface; firmness comes from foam density | memory foam hugs you and some people find it warmer |
| Latex | elastic, recovers quickly | easy to turn over on; air passes through well | feels livelier than conventional foam |
Many mattresses combine layers: a core that provides support (springs or dense foam) and comfort layers on top (memory foam, latex) that set the feel of the surface.
Airflow: a mattress needs to breathe
At night your body gives off heat and moisture, and the mattress takes them in. To stop them building up:
- put the mattress on slats, not straight on the floor or a solid board, so air can move underneath;
- air the room in the morning and leave the bed open for a few minutes before making it;
- rotate the mattress head to foot now and then, if the maker allows it, so it settles evenly;
- use a protector if the mattress cover can't be removed for washing.
Pocket springs naturally leave a lot of air between them. In spring-free mattresses, airflow comes from the materials: latex, coconut fibre and a breathable cover.
The first three weeks: don't judge it on night one
A new mattress almost always feels strange at first, especially if you've spent years on one that had sagged. Your body needs up to about three weeks to adjust. That's normal and doesn't mean the mattress is wrong for you. Only after that is it worth comparing with what you had before.
SpringHero or FoamHero
We sell two mattresses, designed for two different profiles.
| SpringHero | FoamHero | |
|---|---|---|
| Inside | pocket springs | no springs: natural latex (6 cm comfort layer), coconut fibre, 25D foam |
| Firmness | soft | firm |
| Support zones | — | 7 zones |
| Thickness | 25 cm | 23 cm |
| Recommended weight | up to 120 kg | up to 140 kg |
| Cover | knitted, with memory foam quilting; not removable | knitted, removable for washing |
| Certification | Oeko-Tex Standard 100 | — |
| Good if you | sleep on your side | sleep on your back or want a firm surface |
| Warranty | 2 years | 2 years |
| Starting price | the higher of the two | the lower of the two |
Put simply: if you mostly sleep on your side and want a soft, sprung mattress, take SpringHero. If you sleep on your back, weigh more, or just don't like sinking in, take FoamHero. Current prices for each size are on the product pages.
Bed and mattress together
If you're ordering a new bed, it makes sense to get the mattress with it: you know the size fits and they arrive together. There's also a bundle discount when you order a bed and a mattress together.
Frequently asked questions
What mattress should we get if one of us sleeps on their side and the other on their back?
Either pick a middle firmness as a compromise, or get two single mattresses. A 180×200 cm bed takes exactly two 90×200 cm mattresses, each with its own firmness.
Can I put a new mattress on my old slats?
Yes, if the slats are whole, straight and close enough together. A new mattress on broken or sagging slats will quickly dip in the same spot.
Is it normal for a new mattress to smell slightly?
Foam mattresses can have a faint smell when unpacked, from the packaging and materials. Remove the wrapping, air the room and let the mattress stand uncovered before you put the bedding on.
How thick should a mattress be?
There's no required thickness. Keep in mind that a thicker mattress raises you higher and hides more of the headboard; on a bed with 12 cm side rails, a 23–25 cm mattress sits well above them.