When to Replace a Mattress: 7 to 10 Years or 1.5-Inch Sag

Knowing when to replace a mattress is simple: after about 7 to 10 years, or sooner if it sags more than 1.5 inches.

When to replace a mattress by type and age

Age is a starting point, not a deadline. Most published lifespans come from mattress makers and retailers, so they overlap and are not independent tests. Treat 7 to 10 years as the general window for a bed used every night, and let the condition of your bed decide where inside that window you land.

Mattress type	Position in the 7 to 10 year window	What wears out first
Innerspring	Short end	Coils lose tension and padding compresses
Pillow-top	Short end	The soft top layer packs down
Memory foam	Middle	Foam softens and holds body impressions
Hybrid	Middle	Comfort foam wears before the coil base
Latex	Long end	Firmness fades very slowly

A budget bed with thin foam wears out sooner than a dense, well-built bed of the same type, so build quality can move any row up or down.

What shortens or extends the lifespan

• Body weight: heavier sleepers compress foam and coils faster. If that is you, look for sturdier builds in our guide to the best mattress for heavy people.
• Two sleepers: a couple wears the bed faster than one person, and each side wears differently.
• Daily use: a guest bed lasts longer in years than the bed you sleep on every night.
• Support underneath: a weak foundation or missing center support speeds up sagging.

Warranty is not lifespan

A warranty usually covers defects such as sagging past a stated depth, and that depth can differ from the 1.5 inches used in this guide. It does not promise comfort for the whole warranty period, and many warranties exclude stains or a poor foundation. Read yours for its exact terms.

8 signs it is time to replace your mattress

Go through the list and count how many signs apply to you.

1. It has reached 7 to 10 years. Past that point comfort has usually faded even if nothing looks wrong, so take the other signs seriously.
2. Sag deeper than 1.5 inches. A dip you can see with the bed made is already worth measuring, as shown in the next section.
3. Lumps, ridges or hard spots. Filling or foam has shifted or broken down, and the surface no longer feels even under your hips and shoulders.
4. Noise or a felt coil. Squeaks are sometimes the frame, but a coil you can feel through the top means the padding is gone.
5. Tears or exposed padding. Damage to the cover or a collapsed edge is a structural problem that keeps getting worse.
6. You roll toward the middle. If you slide toward a dip or the edge sinks when you sit, support is failing.
7. You wake up stiff or sore. Aches that ease soon after you get up point to poor support or pressure relief.
8. You sleep better somewhere else. A hotel or guest bed that feels clearly better is one of the most useful signals.

Decision rule: replace the mattress if 3 or more of the 8 signs apply. Replace it right away, whatever the count, if you find a broken spring, a tear or sag deeper than 1.5 inches, because a broken spring can also cause injury. With 0 to 2 signs, keep the bed and try the fixes further down.

Comfort often fades before a bed fails structurally, so a mattress can feel worn out well before it looks it.

How to measure sag: a worked example

1. Strip the bedding so the surface is bare.
2. Lay a yardstick, level or broom handle across the dip, with both ends resting on firm, unworn parts of the mattress.
3. Slide a ruler under the middle of the straightedge and read the gap at the deepest point.
4. Repeat on each sleeping side, since two sleepers rarely wear a bed evenly.

Here is one example using typical values for illustration. An 8-year-old hybrid has a ruler reading of 2 inches at the deepest point under the hips. That is 0.5 inch past the 1.5-inch limit. The same bed also shows the following signs:

• Age within the 7 to 10 year window: 1
• Sag deeper than 1.5 inches: 1
• Rolling toward the dip: 1
• Stiff mornings: 1

That adds up to 4 of the 8 signs, and the sag alone is past the limit, so this bed is replaced. A second bed with a 1-inch reading and no other signs would be kept.

Is it the mattress or something else?

Aches and bad sleep have many causes, so test before you spend money.

1. Sleep 3 to 4 nights in a guest bed or hotel bed. One night is not enough.
2. Note how you feel each morning compared with your usual week.
3. Check the pillow, since an old or wrong-height pillow causes neck stiffness.
4. Look under the mattress for broken slats, a bowed frame or a missing center support.

If the pillow and frame check out and you sleep clearly better elsewhere, the mattress is the likely cause. Dust, allergies and stress can also affect sleep, so a new bed will not fix every problem. See a doctor for pain that persists or breathing symptoms that worsen, because a mattress is not a medical treatment.

Can a topper, rotation or new foundation extend mattress life?

Sometimes, but only when the mattress is still structurally sound.

Fix	Worth it when	Not worth it when
Rotating head to foot	Wear is even and no dip has formed	A dip has already formed
Mattress topper	The bed is intact but a bit too firm	The bed sags, because a topper follows the dip
New foundation or slats	Slats are broken or center support is missing	The mattress itself is lumpy or torn
Mattress protector	You want to block spills and dust mites	You expect it to fix sagging or lumps

Follow the manual on rotation schedules and on flipping, since most modern beds are one-sided and should not be flipped. Queen and larger beds usually need center support, so check your manufacturer’s requirements.

A fix only buys time. If the bed already meets the decision rule above, a topper or new slats will hide the problem for a few weeks rather than solve it.

What to do after you decide to replace

Once the signs point to a new bed, our guide on how to choose which mattress to buy walks through types, budget and trial terms.

Our Top Picks

Ready to shop? These are the top-rated options from our hands-on roundup, Best Mattress For Side Sleepers of 2026.

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Frequently Asked Questions

Can a mattress last 15 years?

Rarely. A dense latex or foam bed used by one light sleeper can, but only if it stays free of sag and lumps.

Can I replace just my side of the bed?

Only if the bed is a split design built from two separate halves. A standard mattress is one unit, so both sides are replaced together.

Do guest beds and kids’ beds wear out on the same schedule?

No. A guest bed used a few nights a year can outlast the window, while a kid’s bed is due for replacement when the child outgrows it.

Can I make a warranty claim for a sagging mattress?

Only if the dip meets the depth in your warranty and your foundation meets the maker’s support rules. Read the terms before you measure, and keep your receipt.

Do I need a new mattress after bed bugs?

Not always. Professional treatment and a bed bug-rated encasement can save some mattresses, but a torn cover or severe infestation makes replacement the safer choice.

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