Best pillow for side sleepers: find the right height for your shoulders
Short answer
The best pillow for side sleepers is one tall and firm enough to fill the gap between your ear and the mattress, so your head stays in line with your spine. Broader shoulders need a higher pillow, and a softer mattress needs a lower one. Contoured latex or foam pillows have the most supportive evidence, but height matters more than material.
If you train
Upper-body training changes the fit. Bigger shoulders from swimming, rowing, climbing or lifting widen the gap your pillow has to fill, so a pillow that fit you a year ago may now be too low. If you wake with a stiff neck after heavy pressing or pulling days, check pillow height before blaming the session. Pack your own pillow for race travel, since hotel pillows vary widely and you want one thing in your sleep setup that does not change.
Most adults spend more than half the night on their side. In a study of 664 workers wearing accelerometers, people spent 54% of their time in bed lying on their side 1. That makes the search for the best pillow for side sleepers worth getting right. Your pillow has a harder job on your side than on your back, because it has to fill the full gap between your head and the mattress that your shoulder creates.
This guide covers how to pick pillow height for side sleepers by shoulder width, which materials hold up, and what the evidence says about pillows and neck pain.
What a side sleeper pillow needs to do
When you lie on your side, your shoulder lifts your head away from the mattress. A good side sleeper pillow:
- Fills the gap between your ear and the mattress, so your neck stays in line with your spine.
- Holds that height through the night instead of flattening.
- Supports the neck, not just the head, so the curve of your neck stays relaxed.
Too low and your head tilts down toward the mattress. Too high and it tilts up. Either way, muscles on one side of your neck stay stretched for hours.
The best pillow for side sleepers: what the evidence says
Height and shape matter most
A 2021 meta-analysis of 35 studies on pillow design found that cervical alignment in side-lying depends a lot on the shape and height of the pillow, and much less on whether it is rubber (latex) or feather 3. A lab study on side sleepers tested foam-latex pillows at 8, 10, 12 and 14 cm (about 3 to 5.5 in), with and without a raised neck support 4. The best height for each person was predicted by their shoulder width. A medium height for that person, with neck support, kept the neck curve closest to its natural standing shape and had the lowest muscle load. A slightly lower pillow with neck support felt most comfortable.
That study had only nine people, so treat it as a strong hint, not a rule. A 2021 review of pillow height research agreed that body dimensions, especially shoulder width, are among the key factors, but said there is still not enough evidence to name one optimal height for side or back sleepers 5.
Material and design
- A 2021 systematic review of 11 studies (309 participants) found moderate evidence for a latex pillow, a contoured design with higher sides for side sleeping and a lower middle for back sleeping, a height of 7 to 11 cm (about 3 to 4 in) for the unloaded central part of the pillow, and a cooling surface 2.
- The 2021 meta-analysis found latex (rubber) pillows reduced neck pain compared with other pillows, though the effect was small, and pillow design did not change sleep quality in people with chronic neck pain 3.
- A 2025 review of five newer trials with 239 participants found only limited support for special pillows and no type (latex, foam or standard) clearly better than the others 6.
The honest summary: height and shape have the best support. Latex and contoured foam have some evidence. Expect modest effects, not a cure.
Your mattress changes the right height
A lab study found that on a soft mattress, the head sat lower and the cervical spine curved more than on a medium one, and the authors suggested a softer or thinner pillow for soft mattresses 7. The same logic applies on your side: the more your shoulder sinks into the mattress, the less pillow height you need. Pick your mattress first, then fit the pillow. See our guide to the best mattress for side sleepers.
How to choose pillow height for side sleepers
Step 1: Measure your shoulder
Stand against a wall. Measure from the side of your neck, at the base, to the outer edge of your shoulder. This is roughly the gap your pillow needs to fill, minus how much your shoulder sinks into the mattress.
Step 2: Use a starting range
| Shoulder build | Mattress feel | Starting pillow height (under load) |
|---|---|---|
| Narrow | Soft | About 8 cm (3 in) |
| Narrow | Firm | About 10 cm (4 in) |
| Average | Medium | About 10 to 12 cm (4 to 4.5 in) |
| Broad | Soft | About 12 cm (4.5 in) |
| Broad | Firm | About 12 to 14 cm (4.5 to 5.5 in) |
These ranges sit within the heights tested in the side-sleeper lab study 4. They are starting points, not trial-proven sizes. Height under load means with your head on it.
Step 3: Do the photo test
Lie on your side on your own bed and pillow. Ask someone to photograph you from the front or the back.
- Your nose should line up with the middle of your chest.
- Your head should not tilt down toward the mattress or up toward the ceiling.
- Your lower shoulder should sit slightly forward, not trapped under you.
Step 4: Choose a fill that holds height
- Memory foam or latex block: steady height, firmer feel, can be warm.
- Shredded foam or latex: lets you add or remove fill to adjust height.
- Contoured foam: a higher edge for side sleeping and a lower middle for back sleeping 2.
- Down and feather: soft and moldable, but often too low for broad shoulders unless overfilled.
Step 5: Test at home
Give a new pillow one to two weeks. Many makers offer home trials. Prefer pillows you can return or adjust, because bodies react differently.
Step 6: Add a knee pillow if your hips twist
If your top knee drops forward onto the mattress, your pelvis and lower back rotate. A firm pillow between the knees keeps the legs stacked. There are no large trials on this, but it is cheap, safe and many side sleepers find it eases hip and low back discomfort. Hugging a second pillow in front of your chest does the same for the top shoulder.
For people who train
Sleep is when your body repairs after training, and a 2021 expert consensus on athlete sleep calls for an individual approach to athlete sleep rather than a one-size-fits-all rule 9. Your pillow is a small part of that, but it is easy to get right.
- Shoulder size changes. Swimmers, rowers, climbers and lifters often have broader shoulders and need more height than average.
- Neck soreness after training can come from the session or the pillow. If it shows up every morning, check the pillow first.
- Travel. Hotel pillows vary a lot. Packing your own keeps your setup constant before a race.
- Wind down. A few minutes of gentle neck and shoulder mobility, like our stretches before bed, can help you settle.
- Hours first. A good pillow does not make up for short sleep. Use the sleep calculator to plan bedtime.
Common mistakes
- Choosing a pillow by shelf height. A fluffy pillow can flatten to half its height under your head.
- Stacking two soft pillows. It often leaves a gap under the neck. One firm pillow of the right height works better.
- Keeping a pillow that has gone flat. If you fold it in half and it stays folded, it has lost its support.
- Ignoring the mattress. A new, softer mattress may mean you need a lower pillow 7.
- Sleeping with an arm under the pillow. It often means the pillow is too low.
Pillows and neck pain
In a meta-analysis of 30 studies with 18,395 college students, improper pillow use was linked to about twice the odds of neck pain (odds ratio 2.20) 8. Most of those studies were surveys, so they show a link rather than proof of cause. If neck pain is your main concern, see our guide to the pillow for neck pain, and read about the best sleeping position for your neck.
When to see a doctor
A pillow can make sleep more comfortable, but it does not treat neck conditions. See a doctor or physical therapist if neck pain lasts more than a few weeks, follows an injury, or comes with arm pain, numbness, tingling, weakness or headaches that wake you.
When to see a doctor
See a doctor if neck pain lasts more than a few weeks, follows an injury, or comes with arm pain, numbness, tingling, weakness or headaches that wake you.
Frequently asked questions
What pillow height is best for side sleepers?
It depends on your shoulder width and your mattress. A lab study on side sleepers tested pillows from 8 to 14 cm (about 3 to 5.5 in) and found the best height scaled with shoulder width. Broad shoulders need the higher end, narrow shoulders the lower end. A soft mattress lets your shoulder sink, so you need less height. Check with a photo: your nose should line up with the center of your chest.
Should side sleepers use a firm or soft pillow?
Medium-firm to firm usually works best for side sleepers, because a soft pillow compresses under the weight of your head and loses height overnight. What matters is the height when your head is on it, not the height on the shelf. If a soft pillow feels great but you wake with neck pain, it is probably flattening. Try a firmer fill or add a second thin pillow.
Are memory foam pillows good for side sleepers?
They can be, because foam holds its height through the night. A meta-analysis found latex (rubber) pillows reduced neck pain slightly compared with other pillows, and a newer review found no single material clearly better. Choose foam or latex if feather pillows flatten on you. Shredded foam lets you remove fill to fine-tune the height. Memory foam can feel warm.
Can the wrong pillow cause neck pain?
It can contribute. In a meta-analysis of risk factors among college students, improper pillow use was linked to about twice the odds of neck pain. Those were mostly survey studies, so they show an association, not proof of cause. Trials that changed pillows found small improvements in neck pain and waking symptoms. If pain lasts more than a few weeks, see a professional.
Should side sleepers put a pillow between their knees?
Many side sleepers find it more comfortable. A pillow between the knees keeps the top leg from rolling forward and twisting the pelvis and lower back. There are no large trials on this, but it is cheap and safe to try. Hugging a second pillow in front of your chest can also take load off the top shoulder.
Sources
- Skarpsno ES et al. (2017). Sleep positions and nocturnal body movements based on free-living accelerometer recordings: association with demographics, lifestyle, and insomnia symptoms. Nature and Science of Sleep.
- Radwan A et al. (2021). Effect of different pillow designs on promoting sleep comfort, quality, and spinal alignment: A systematic review. European Journal of Integrative Medicine.
- Chun-Yiu JP et al. (2021). The effects of pillow designs on neck pain, waking symptoms, neck disability, sleep quality and spinal alignment in adults: A systematic review and meta-analysis. Clinical Biomechanics.
- Tian S et al. (2024). The individualized optimal pillow height and neck support design for side sleepers. Medical and Biological Engineering and Computing.
- Lei JX et al. (2021). Ergonomic Consideration in Pillow Height Determinants and Evaluation. Healthcare (Basel).
- Ghosh S et al. (2025). Effect of pillow on pain, disability and sleep quality in patients with chronic neck pain: A systematic review. Rehabilitacion (Madrid).
- Hong TT et al. (2022). The Influence of Mattress Stiffness on Spinal Curvature and Intervertebral Disc Stress: An Experimental and Computational Study. Biology (Basel).
- Gao Y et al. (2023). Risk factors for neck pain in college students: a systematic review and meta-analysis. BMC Public Health.
- Walsh NP et al. (2020). Sleep and the athlete: narrative review and 2021 expert consensus recommendations. British Journal of Sports Medicine.