Choose the mattress first, for your body and the way you sleep. Then fit each sleeper's pillow while lying on that mattress, in their real position.
Why that order? A softer or firmer mattress changes how high your head sits. So you can only judge a pillow on the bed it'll live on.
| You change to | What happens under your shoulder | What it can do to your pillow | Check |
|---|---|---|---|
| One of the softer mattresses, or one that contours more deeply | Your shoulder and hip can sink further | The gap between your head and the mattress can shrink. On your side, the same pillow can sit too high | Lie on your side and see whether your head tips up toward the ceiling |
| One of the firmer mattresses | Your shoulder is held up nearer the surface | The same pillow can feel too low | See whether your head drops toward the mattress |
| A plush layer from the mattress toppers added on top | The surface acts like a softer mattress | Same as a softer mattress, so the pillow can sit higher | Re-check the pillow once the topper goes on |
| Same mattress, new pillow | Nothing changes under your shoulder | Only the pillow changed | Judge the new pillow on its own |
Why the Same Pillow Feels Different on a New Mattress
Your pillow didn't change. The space it has to fill did.
A softer or more contouring mattress lets your shoulder and hip sink further. So when you sleep on your side, the same pillow can push your head higher than before. A firmer mattress holds your shoulder up, and the same pillow can suddenly seem flat.
Pillows compress under your head, and mattresses give under your body. The height that counts is what's left under your head once both have given, not the height on a label. Softer fills often compress more than firmer ones.
Researchers writing in PeerJ note that "there are no universal, evidence-based guidelines for pillow design or selection." In their small lab study, raising pillow height changed the curve of the neck. It also changed the pressure under the head and neck.
No chart can hand you a number. Lying on the pair is the test.
What a Pillow Should Do in Each Sleep Position
The University of Rochester Medical Center's health encyclopedia sets one goal for every position. It says, "Regardless of your sleeping position, try to keep your ears, shoulders, and hips aligned." It adds that the head pillow "should support the natural curve of your neck and be comfortable."
| Position | What URMC says the pillow should do | Extra pillow URMC mentions | On a softer vs firmer mattress |
|---|---|---|---|
| Side | "The pillow for your head should keep your spine straight." | "A firm pillow between your knees will prevent your upper leg from pulling your spine out of alignment." | On a softer mattress your shoulder can sink, so check you're not propped too high. On a firmer one, check your head isn't dropping. |
| Back | It "should support your head, the natural curve of your neck, and your shoulders." | "A small pillow under the back of your knees will reduce stress on your spine." | Look from the side to check your head isn't pushed forward. Re-check whenever the mattress changes. |
| Stomach | It "should be flat, or sleep without a pillow." | "Placing a flat pillow under the stomach and pelvis area can help to keep the spine in better alignment." | A deeper mattress can change how your hips sit. Check that your ears, shoulders and hips still line up. |
Do you change position through the night? URMC says "your pillow should be adjustable to allow you to sleep in different positions."
The same page also cautions that "a pillow that's too high can put your neck into a position that causes muscle strain on your back, neck, and shoulders." If your back is what's sore, see how to choose a pillow for back pain.
How Pillow Fills Hold Their Height
The fill decides how much a pillow gives under your head, and whether you can change its height. Look at it first when you compare pillows.
Memory foam
It shapes slowly around your head and holds that shape. The height is set by the pillow you buy.
Latex
It's springier, and it pushes back rather than sinking slowly. The height is fixed here too.
Down and feather
It's moldable and compresses a lot. You can fluff it up or fold it to change the height for a night.
Polyester fiber
It's soft, and it can flatten over time. There's little you can do to adjust it.
Shredded foam or other adjustable fill
You add or remove fill to raise or lower the height. That's useful when your mattress changes.
How long does a pillow keep its height? Watch for a pillow that stays flat, turns lumpy or doesn't recover its shape. Having to fold it for enough height is another sign.
Any of these means it no longer gives the height it did. For care, follow the maker's label.
Which to Change First, the Pillow or the Mattress
Change the cheaper, quicker variable first. And change only one thing at a time.
My neck hurts in the morning. Is it the pillow or the mattress?
Start with a comfort check. Lie in your usual position and have someone check that your ears, shoulders and hips line up, the alignment URMC recommends. URMC also says to "insert pillows into gaps between your body and the mattress."
Some neck pain needs a provider. MedlinePlus advises contacting one if your neck pain:
- comes with "numbness, tingling, or weakness in your arm or hand"
- was "caused by a fall, blow, or injury"
- "gets worse when you lie down or wakes you up at night"
That's a question for a doctor, not for bedding.
New mattress, and my pillow feels wrong. Should I exchange the mattress?
Test the pillow height first. For one night, slip a folded towel under the pillowcase, or take some fill out of an adjustable pillow. Change nothing else.
If a different height feels better, the pillow is the piece to change. A topper counts as a mattress change, so keep it out of this test.
If height makes no difference, then look at the mattress. If it came with a trial or comfort guarantee, check the terms early.
Do I need a new pillow with a new mattress, and is a pricier one worth it?
Not always. Your current pillow may still work once you check it on the new surface.
A pillow's price is driven mostly by its fill, whether its height can be adjusted, and its cover. To judge value, ask one thing: does it keep the height you need on your mattress? You find that out by lying on the two together, not by reading the tag.
We share a bed but sleep differently. What do we do?
One mattress, two pillows. URMC says that if you share the bed, "you should have enough space to move into a comfortable sleeping position."
Agree on the mattress together. Then each of you fits your own pillow to your own position on it.
Fit the Pair in This Order
- Settle the mattress's support level first. Mancini's Sleepworld's comfort guide groups mattresses as Extra Firm, Firm, Medium Firm and Soft. For a starting point, try SleepMatch. You can take the online quiz, or get a body scan at a SleepMatch location for a color-coded report.
- Lie on two or three finalists side by side. Visit a Mancini's Sleepworld location (there are 50+ across Northern California) to try many brands side by side. Lie in your real sleep position, with the pillow you sleep on now. You'll see how each mattress changes that pillow's height before you buy either. Keep in mind that one brand's "medium" may not feel like another's.
- Have someone look at you side-on. They check that your ears, shoulders and hips line up, the alignment URMC recommends. A phone photo makes your finalists easier to compare.
- Then try pillow heights on that exact mattress. A display shelf can't tell you how a pillow will sit on your bed. Once a mattress stands out, ask a Sleep Specialist whether you can try pillows from the range while lying on it. Where a pillow listing gives a height, note it. Just remember that the height left under your head is what counts.
- Each sleeper fits their own pillow. Partners share the mattress, but not the pillow decision.
- At home, change one thing at a time. If you add a topper later, re-check the pillow. The surface under your shoulder has changed.
From here, shortlist two or three mattresses at your support level and lie on them at a Mancini's Sleepworld location.