--- title: "Knee pillow listings, by the numbers · The Side Sleeper" url: https://thesidesleeper.com/knee-pillows/findings/ published: 2026-10-09 updated: 2026-10-09 --- [Knee pillow guides](https://thesidesleeper.com/knee-pillows/) # Knee pillow listings, by the numbers **Nell, the Side Sleeper** Updated October 9, 2026 · Data collected October 5, 2026 · [How we research](https://thesidesleeper.com/how-we-research/) **Most knee pillow listings leave out the number that matters most.** 10 of the 24 best sellers on Amazon US don't give a usable thickness, and most "cooling" claims are about the cover, not the foam. These are counts from the specs of the 24 best-selling knee pillows, collected October 5, 2026. Nothing was measured by hand: every number comes from the listing text or the maker's own page. ## 10 of 24 best sellers give no usable thickness 10 of the 24 best-selling knee pillows on Amazon US don't state a usable thickness, the one number that decides fit. That includes the #1 best seller, the Contour Legacy Leg & Knee Pillow, with 43,734 reviews. Of those 10, 6 leave it to the photos, and 4 give several numbers without saying which is the gap between your knees, or contradict themselves. [How thick should a knee pillow be?](https://thesidesleeper.com/knee-pillows/thickness/) ## Compact knee pillows are 5–7.2 inches thick Of the 14 knee pillows that state their thickness, the compact between-the-knees shapes are 5 to 7.2 inches thick (outer height), and the long ones that run down the thigh or leg are 3 to 6.5 inches. The median across all of them is 5.85 inches. [Find your own number with the towel test](https://thesidesleeper.com/knee-pillows/thickness/) ## Only 7 of 14 fit the "4 to 6 inches" rule Sleep guides often say a knee pillow should be 4 to 6 inches thick. Of the 14 best-selling knee pillows that state a thickness, only 7 fall in that range: 5 are thicker and 2 are thinner. [Why the rule is only a starting point](https://thesidesleeper.com/knee-pillows/thickness/) ## 19 of 24 are solid memory foam 19 of the 24 best-selling knee pillows are a solid block of memory foam. The rest are shredded foam, polyester fibre or foam with removable inserts, and one listing contradicts itself on what's inside. [Knee pillow fillings, explained](https://thesidesleeper.com/knee-pillows/fillings/) ## 17 claim "cooling", 2 change the foam 17 of the 24 best-selling knee pillows claim to keep you cool, but only 2 do anything to the foam itself, such as a gel layer or vent holes. For the other 15, "cooling" means the cover fabric. [What "cooling" means on a listing](https://thesidesleeper.com/knee-pillows/fillings/) ## 9 say "high-density", none give a figure 9 of the 24 listings describe their foam as "high-density" or similar, and 8 promise it won't flatten. None of them gives a density or firmness figure to back that up. [Fillings by the numbers](https://thesidesleeper.com/knee-pillows/fillings/) ## 6 of 24 come with a strap 6 of the 24 best-selling knee pillows include a strap to keep them on your leg, 7 have none, and 11 don't say. [Strap or no strap?](https://thesidesleeper.com/knee-pillows/how-to-use/) ## A compact knee pillow costs about $31 The median price of a compact best-selling knee pillow was $31 ($17 to $45) on October 5, 2026. Long and full-leg pillows had a median of $37. [Every pillow and its price](https://thesidesleeper.com/knee-pillows/compared/) ## 18 of 24 say they're machine washable 18 of the 24 listings say the cover, or the whole pillow, goes in the washing machine. Only 3 name a CertiPUR-US foam certificate. [Washing, smell and certificates](https://thesidesleeper.com/knee-pillows/fillings/) ## Where these numbers come from The set is the between-the-knees pillows in Amazon US's best-seller list for leg positioner pillows (ranks 1 to 77), one from its medical-pillow list and two brands that sell direct. The one body pillow in the comparison is left out of these counts. Prices and ratings move daily; the counts are as of October 5, 2026. The full table, with how each thickness was sourced, is at [knee pillows compared](https://thesidesleeper.com/knee-pillows/compared/), and the raw data is free to reuse: [CSV](https://thesidesleeper.com/data/knee-pillows.csv) · [JSON](https://thesidesleeper.com/data/knee-pillows.json). ## Citing this page The Side Sleeper, "Knee pillow listings, by the numbers", data collected October 5, 2026. https://thesidesleeper.com/knee-pillows/findings/ ## Keep reading [### Why sleep with a pillow between your knees?](https://thesidesleeper.com/knee-pillows/benefits/)[### How thick should a knee pillow be?](https://thesidesleeper.com/knee-pillows/thickness/)[### Pillow between your knees hurts your hips?](https://thesidesleeper.com/knee-pillows/hurts-hips/)[### How to use a knee pillow](https://thesidesleeper.com/knee-pillows/how-to-use/)[### Knee pillow vs body pillow vs a regular pillow](https://thesidesleeper.com/knee-pillows/vs-body-pillow/)[### Knee pillow shapes, explained](https://thesidesleeper.com/knee-pillows/shapes/)[### Knee pillow fillings, explained](https://thesidesleeper.com/knee-pillows/fillings/)[### Knee pillows compared](https://thesidesleeper.com/knee-pillows/compared/)