You need a new mattress when it shows wear you can see, feel or hear: a dip that stays when you get up, lumps or springs felt through the top, creaking springs, or edges that sink when you sit. It is also time if other beds feel more comfortable, or it no longer suits how you sleep.
- If the dip is in the middle of the bed: look for springs that are firmer through the centre, like the 3-zone core in the Sleep Bliss Memory Foam Mattress.
- If you sit on the edge to dress: look for reinforced edges, like the firmer spring rows around the Supreme Care 5 Zone Memory Foam Mattress.
- If your bed sleeps warmer than others: look at the top layer, like the gel memory foam in the Cool Night Gel Memory Foam Mattress, designed to feel cooler than standard memory foam.
In this guide
How to tell if your mattress is worn out
Wear shows up best on a bare mattress in daylight, so run this ten-minute check the next time you change the sheets.
- 1. Strip it bare. Take off the sheets, the protector and any topper, which can hide a hollow.
- 2. Look along it, not down at it. Crouch at the foot of the bed with light coming from one side, which picks out hollows and ridges you miss from above.
- 3. Lay a straight edge across it. Rest a broom handle from side to side where your hips lie. A gap underneath is a dip. Compare it with the same test near the foot of the bed.
- 4. Run your hands over it. Press with flat palms across the whole top, feeling for lumps, hollows and springs through the padding.
- 5. Sit on both edges. Sit where you would to put your shoes on. Does the edge hold you, or drop away and tip you forward?
- 6. Lie down and roll over. Turn a few times in your usual position. Listen for creaks, and notice whether you roll towards a hollow.
One sign on its own may have a simple cause, so read what to rule out before you decide. Several signs together usually mean the mattress is worn out.
Pieces in this guide
Mattress sagging: wear or normal settling?
Every mattress changes a little once it is slept on. The comfort layers soften and take a slight, even shape where you lie, and a new rolled mattress keeps settling for a few days after unboxing. That is normal settling, not wear.
Sagging means the support underneath has gone. These are the signs:
- a dip you can see with the bedding off, still there when you get up;
- you roll towards the dip during the night;
- two hollows with a ridge between them, if two of you share the bed;
- springs you can feel through the top where it dips.
Sagging usually starts in the middle of the bed, because lying down, your hips and lower back are the heaviest part of you. A topper will not fix it: it changes how the surface feels, but it sits in the same dip.
Lumps, noisy springs and soft edges
Lumps, and springs you can feel
The padding in a quilted top can thin or bunch with use. Once you can feel ridges, hollows or individual springs through the top, that layer has stopped cushioning you from the core. Rotating the mattress moves a lump to the other end; it does not smooth it out.
Noisy springs
Creaks and squeaks often come from the bed frame, not the mattress. Tighten the bolts, check every slat sits in its holder, and press on the frame with the mattress off. If the noise only comes when you move on the mattress, try lying on it on the floor. If it still creaks there, the springs are usually wearing, and no amount of tightening will fix that.
Edges that give way
A worn edge sinks steeply when you sit on it and tips you forward. Lying down, the outer strip feels as if it is rolling you out, so you drift towards the middle. That narrows the part of the bed you can actually use, which matters most when two of you share it.
When the mattress is sound but no longer suits you
A mattress can pass every check above and still be wrong for you. These signs count too:
- Other beds feel better. If you sleep better on the spare bed or away from home, compare like with like: the same pillow, similar bedding, a similar room temperature. If your own bed still comes off worse, the mattress is the likely difference.
- You wake up warmer in it. Rule out a heavy doona or a plastic-backed protector first. If the mattress itself still sleeps warmer than other beds, look at the top layer of the next one: see our guide for hot sleepers.
- The way you sleep has changed. You now sleep on your side, share the bed, or wake when a partner moves. How firm a mattress feels varies with body weight and sleeping position, so a feel that suited you once may not suit you now.
Our guide to mattress firmness by sleeping position matches each position to a feel. Every mattress in this guide shows a feel label and a score out of 10 on its product page, and you can browse soft and plush mattresses, medium firm mattresses and firm mattresses.
Rule these out first
Some problems look like a worn mattress but are not, so check these before you replace it.
- The base. Lift the mattress off and lay your straight edge across the base. A sagging base, or a slat that is cracked, missing or out of its holder, leaves even a sound mattress unsupported. Each mattress page in this guide asks for a solid or platform base, or evenly spaced slats, and gives about 7.5 cm as a general guide: wider gaps between slats can leave a mattress under-supported.
- Rotation. If one end has always taken the weight, turn the mattress head-to-foot and check again in a couple of weeks. Every mattress in this guide is single-sided, so rotate it rather than flip it. Rotating spreads the wear; it will not lift a dip.
- Smells and marks. Clean before you replace: our step-by-step guide to cleaning a mattress covers stains, smells and drying. A smell that keeps coming back however often you clean is a sign, though.
What to look for in the next mattress
Match the next mattress to the sign that sent you shopping:
| Sign | Look for | Examples |
|---|---|---|
| A dip in the middle | Zoned springs, firmer through the centre | Sleep Bliss (3 zones); Supreme Care and Cradle Rest (5 zones) |
| Edges that sink | Reinforced edges: firmer springs around the perimeter, or a firm foam border | Supreme Care and Sleep Bliss (spring rows); Sleep Serenity (foam border) |
| Feeling a partner move | Individually wrapped pocket springs | All the mattresses in this table, plus the Sleep Pure |
| Waking warm | A gel memory foam top, designed to feel cooler than standard memory foam | Cool Night |
| Stains and smells | A waterproof protector from the first night | Waterproof Mattress Protector; Mellow Pillow Bamboo Waterproof Mattress Protector |
The Sleep Bliss Memory Foam Mattress puts a memory foam top over a 3-zone pocket spring core that is firmer through the centre, with two rows of firmer springs reinforcing the edges. Its page labels it Firm, 7 out of 10. The Supreme Care 5 Zone Memory Foam Mattress is the softer choice, labelled Plush, 4 out of 10, with a 5-zone core and two firmer 2.3 mm spring rows around the perimeter. The Cradle Rest 5 Zone Pocket Spring Mattress sits between them at Medium, 5 out of 10.
The Sleep Serenity Pocket Spring Mattress reinforces its edges another way, with a firm foam border around the springs that its page says gives a sturdier seat on the edge of the bed. The Sleep Pure Pocket Spring Mattress and the Cool Night Gel Memory Foam Mattress are both labelled Medium-Firm, 6 out of 10, and the Cool Night's page calls its gel memory foam a cooler-feeling surface rather than active cooling. Our guide to pocket spring, Bonnell and foam mattresses explains the spring types.
Protect the new mattress from the first night. The Waterproof Mattress Protector has a cotton terry surface over a PU (polyurethane) backing that stops spills, sweat and accidents reaching the mattress, and the Mellow Pillow Bamboo Waterproof Mattress Protector does the same with a bamboo surface. Both are machine washable on a gentle cycle, away from high heat; find them with our bedding and mattress protectors.
Firmness is personal, so lie on a mattress in your usual position before you decide. Our five showrooms are in Rocklea, Virginia, North Ipswich, Bundall and Beenleigh. Not every mattress is on display at every store, so ask which store has it on display before you visit.
Replacing a mattress: your questions
When should you replace a mattress?
When it shows the signs in this guide, not on a set date. How long a mattress stays comfortable depends on how it is built, used and looked after, so check it each time you rotate it.
Can a sagging mattress be fixed?
Not once the support has worn. Rotating spreads future wear and a topper changes how the surface feels, but neither lifts a dip that is already there. If the base or its slats are what is sagging, though, fixing them may be all you need.
What causes a dip in the middle of a mattress?
Your hips and lower back are the heaviest part of you lying down, so the layers and springs under them wear first. A sagging base or slats spaced too far apart can cause the same dip, so check the bare base before you blame the mattress.
How can you tell a worn mattress from one that just needs rotating?
Rotate it head-to-foot and check again after a couple of weeks. If the bed feels even again, one end had simply taken more weight. If you can still see a dip with the bedding off, the mattress has worn.
Should you buy a firmer mattress if your old one sagged?
Not necessarily. Sagging is worn support, while firmness is how the surface feels. Look for a core that holds you level, such as springs that are firmer through the centre, in the feel that suits how you sleep. A mattress that is too firm for you can leave gaps under parts of your body.