Best pillow for side sleepers: what to look for

The best pillow for a side sleeper is one that fills the space between the ear and the mattress, so the head stays in line with the spine instead of tipping down or being pushed up. In practice that usually means a higher loft and a medium firm to firm feel, but the right height depends on your shoulder width, your mattress and the fill. This guide explains what to check, rather than recommending specific products.

Why side sleepers need a different pillow

When you lie on your side, your shoulder holds your upper body off the mattress. That leaves a gap between your head and the bed roughly the width of your shoulder. A pillow that is too low lets the head drop; one that is too high pushes it up. Many side sleepers find they need more height and more support than back or stomach sleepers.

1. Loft: how tall the pillow is

Loft is the height of the pillow before you lie on it. Side sleepers usually need a high or medium high loft. What matters most is the height under the weight of your head, not on the shelf, because soft fills compress a lot. A simple starting point is to measure from the side of your neck to the edge of your shoulder. That distance is roughly how high the pillow needs to stay once your head is on it.

2. Firmness: how much it holds up

Firmness is how much the pillow resists the weight of your head. Side sleepers usually do better with medium firm to firm, so the pillow keeps its height through the night. A firmer pillow often simply contains more fill: in our review of 42 hotels, one hotel chain's soft pillow held 800 g of fill and its firm version 1000 g. For firmness by sleep position, see soft, medium or firm pillow.

3. Gusset: the side wall

A gusset is a strip of fabric sewn around the edge of the pillow. It gives a box shape with straight sides, instead of a pillow that tapers to thin edges. A gusseted pillow holds a more even height across its whole surface, which suits side sleepers because the head and neck rest near the edge closest to the shoulder. A deeper gusset gives a taller, more even pillow.

4. Fill: how it behaves

For a closer comparison of natural and synthetic fills, see down vs feather vs down alternative.

5. Shoulder width and body size

Broad shoulders create a bigger gap, so they usually call for a taller or firmer pillow. Narrow shoulders or a smaller frame suit a lower loft. If you share a bed, you may each need a different pillow even if you both sleep on your side.

6. Your mattress

A soft mattress lets the shoulder sink in, which shrinks the gap under the head, so go a step lower or softer. On a firm mattress the shoulder stays higher, so you may need more height. If you change your mattress, your pillow may need to change too.

A quick checklist

• Lie on your side for a few minutes. Your nose should line up with the centre of your chest, not point up or down.
• Your shoulder should rest on the mattress, not on the pillow.
• You should not need to put your arm under the pillow to prop your head.
• The pillow should keep its height after you have been lying on it for a while.
• If you move between positions, an adjustable or mouldable fill may suit you better than a fixed shape.

Other things worth checking

• Size. A standard size suits most people, and a longer pillow gives more room if you move around. See pillow types and sizes explained.
• Shell fabric. A tightly woven cotton shell keeps feather and down fill in and breathes well.
• Care. Check whether the pillow is machine washable before you buy.
• A second pillow. Many side sleepers add one between the knees or one to hug. See how many pillows to sleep with.