Pillow Between Your Knees: A Side-Sleeper Guide
Side Sleeper & Pillow Comfort
Putting a pillow between your knees is one of the simplest changes a side sleeper can make. It stops your top leg sliding forward, keeps your knees from pressing together and helps your hips stay more level. Here is how to do it well.
Quick answer
Lie on your side, bend your knees slightly and place a pillow between them so your knees sit roughly hip-width apart. A folded regular pillow is fine to start with. If it keeps slipping, try a contoured knee pillow with a strap, or a long body pillow.
Why use a pillow between your knees?
When you lie on your side without support, your top knee often drops down and forward onto the bottom one. This can gently twist your hips and lower back, and leave your knees feeling uncomfortable where they press together.
A pillow fills that gap. Many side sleepers find it makes the position feel more relaxed and settled, particularly if they often wake up feeling stiff. It is a comfort aid, not a treatment, and everyone's experience is a little different.
How to position it
- Lie on your side with your head on a pillow of the right height.
- Bend your knees slightly, so they are a little in front of your hips.
- Place the pillow between your knees, with the top of it just above the knee joint.
- Check your hips. Your top knee should be roughly level with your top hip, not dropping down.
- Try your ankles too. Some people prefer a longer pillow that runs from knees to ankles, so the whole leg is supported.
How thick should it be?
Thick enough to keep your knees about hip-width apart. If it is too thin, your top knee still drops. If it is too thick, your top leg is pushed up awkwardly. People with wider hips often prefer a slightly thicker pillow.
Which type of pillow?
| Option | Good for | Things to consider |
|---|---|---|
| Folded regular pillow | Trying it out tonight at no cost | Can be bulky and may slip out |
| Contoured knee pillow | A neat, shaped fit between the knees | Look for a washable cover; a strap helps it stay put |
| Long body pillow | Supporting knees, legs and top arm together | Takes up more space in the bed |
How to stop it slipping out
- Choose a contoured shape that sits between your knees rather than a flat one.
- Use a strap if your knee pillow has one, fastened gently around one leg.
- Try a body pillow, which you can hug and hold between your knees at the same time.
- Use a smooth pillowcase so it moves with you when you turn over.
For more on choosing a shape, see how to choose the right pillow shape for your sleep style.
Common mistakes
- Placing it too low. Between the calves only, it does little for your hips.
- Using one that is too thick. Your top leg should feel relaxed, not propped up.
- Forgetting your head pillow. Knee support works best alongside the right head pillow. See how to build a comfortable side-sleeper setup.
Knee pillow checklist
- Knees slightly bent
- Pillow just above the knee joint
- Knees roughly hip-width apart
- Top leg relaxed, not pushed up
- Stays in place when you turn
A note on your health
This article offers general comfort information, not medical advice. If you have ongoing hip, knee or back pain, are recovering from surgery or are pregnant, please ask your GP, physiotherapist or midwife about the best sleeping position for you.
Frequently asked questions
Can I use any pillow between my knees?
Yes. A regular pillow folded in half is a good way to see whether you like it before buying anything.
What if it falls out in the night?
That is very common. A contoured pillow with a strap, or a body pillow you can hug, tends to stay in place better.
Can back sleepers use a knee pillow?
Some back sleepers like a pillow under their knees instead. It is a different position, but the idea of filling gaps is the same.
Final thoughts
A pillow between your knees is a small, low-cost change that many side sleepers find makes a real difference to comfort. Try a folded pillow tonight and see how it feels.
For more ideas, read 7 ways to sleep more comfortably on your side or the ultimate side-sleeper comfort checklist.