How to choose a pillow that actually fits you

Start with how you sleep

The gap a pillow needs to fill is the space between your head and the mattress when your spine is in a neutral line. That gap changes with position, which is why one pillow rarely suits a whole household.

If you mostly sleep on your side, that gap is wide: roughly the width of your shoulder. You need height to keep your head from tipping down toward the mattress. On your back the gap is smaller, so a medium height works better. Face down, the gap is almost nothing, and a thick pillow will push your neck backwards all night.

• Side sleeper: higher loft, firmer support
• Back sleeper: medium loft, gently contoured
• Front sleeper: low loft, soft
• Mixed: adjustable fill you can add to or remove

Firmness is not the same as height

These get confused constantly. Height is how far the pillow lifts your head. Firmness is how much it resists when you press into it. A tall soft pillow can compress down to almost nothing under the weight of your head, which is why a pillow that felt generous in the shop can feel flat by 2am.

If you like a soft feel but need height, look for a firmer core with a softer top layer rather than a single soft fill throughout.

How to tell yours is wrong

You do not usually notice a bad pillow while you are asleep. You notice it in the first ten minutes after waking.

• You wake with a stiff neck or a dull ache across your shoulders
• You fold the pillow in half, or stack a second one on top
• You wake up having pushed it aside entirely
• You keep flipping it looking for a comfortable spot

A simple test before you buy

Lie down the way you normally sleep and have someone look at you from the front. Your nose should line up roughly with the centre of your chest, and your chin should not be tucked toward your throat or tilted up toward the ceiling. If your head is propped up or drooping, the height is off.

Give a new pillow a fortnight before deciding. Necks adapt slowly, and the first few nights on any unfamiliar support feel strange even when the height is right.

What the fill is made of

Fill affects feel as much as height does. Memory foam, whether in one solid piece or cut into small pieces, is slow to respond: it holds the shape you press into it and takes a moment to spring back, which is why it can feel different to lie on than it does to press with a hand in a shop. Down and feather blends are light and soft and mould readily around your head, but need regular fluffing to stop them settling into flat patches through the night. Synthetic fibre fill, often polyester, is the most affordable option and washes easily, but tends to compress faster and often needs replacing sooner as a result. Latex holds a steady shape night after night and resists the lumps other fills can develop over time, though it is heavier and firmer than most people expect.

None of these is simply better than the others — the right one depends on how much give you want, how warm you tend to sleep, and how much upkeep you are willing to do.

• Memory foam: contoured support, slow to respond, keeps its shape well
• Down and feather: soft and light, needs regular fluffing
• Synthetic fibre: affordable and washable, softens fastest
• Latex: firm and consistent, resists lumps, heavier to handle

When to replace it

Even the right pillow does not last forever. Fold it in half and let go: a pillow with useful life left will spring back toward its original shape within a few seconds. One that stays folded, or has visible lumps and dips where your head rests most nights, is no longer doing its job, no matter how carefully you have looked after it.

How long that takes varies with the fill and how the pillow is used. A firm latex pillow can hold up through years of nightly use, while a soft synthetic one may need replacing well before that. Washing the cover and airing the insert helps it last, but will not stop a fill from eventually breaking down. If you keep waking with the stiffness or ache described earlier, even after checking the height and giving it a fair trial, treat that as a sign the pillow itself is worn out rather than persisting with it.