A 24×24 pillow cover needs a 26×26 insert to look properly filled, with 28×28 as a fuller, firmer option.
Choosing the right insert for a 24×24 cover comes down to one rule: size up. An insert matching the cover exactly will leave your pillow looking flat and floppy. The sweet spot is 1 to 4 inches larger than the cover, and for a 24×24 cover, that points squarely at 26×26 or 28×28.
Here’s the breakdown of which size to choose, why bigger works better, and the few mistakes that leave throw pillows looking deflated.
Why a 26×26 Insert Is the Standard Choice
The 26×26 insert is the most frequently recommended size for a 24×24 cover. Trusted sizing guides from manufacturers like Chloe and Olive and Mississippi Stitches both list 26×26 as the default match for a 24×24 cover. That extra 2 inches on each side is what gives the pillow its structure.
That overfill pushes against the seams of the cover, which does two things: it makes the corners look crisp and full, and it keeps the fabric taut so wrinkles stay minimal. A same-size insert, by contrast, leaves the cover loose with a soft, sagging center — the look most people are trying to avoid.
When to Pick a 28×28 Insert Instead
A 28×28 insert is the right call when you want a noticeably fuller, firmer pillow or when your cover is made from a thick, heavyweight fabric. Thicker fabrics like linen blends or heavy velvets absorb more of the insert’s shape, so they need a larger insert to look filled out rather than lumpy.
The trade-off is overstuffing. If the fabric is delicate or the seams are tightly constructed, a 28×28 insert can strain the stitching. Arianna Belle’s sizing guide notes that some makers recommend a 27×27 insert for 24×24 covers, specifically because the larger size works better with thicker fabrics while avoiding the strain of a full 4-inch jump.
Pillow Insert Sizes for 24×24 Covers
| Insert Size | Look Achieved | Best For |
|---|---|---|
| 24×24 | Flat, sagging, deflated | Avoid this size entirely |
| 26×26 | Full, crisp, standard | Most cotton and poly-blend covers |
| 27×27 | Fuller, structured | Thicker fabrics needing a mid-size fill |
| 28×28 | Plush, firm, overstuffed | Heavyweight fabrics, bold look |
When you’re ready to buy the cover itself, our tested roundup of the best 24 x 24 pillows covers the top-rated options worth your money.
Common Sizing Mistakes to Avoid
The most common error is buying an insert the same size as the cover. It seems logical, but it produces a pillow that looks half-empty. The second mistake is ignoring the fabric. A lightweight cotton cover will look great with a 26×26, while the same insert can look undersized inside a thick boucle cover that eats up volume.
A final note on manufacturer variance. Chloe and Olive’s insert sizing guide recommends 26×26, while Arianna Belle’s sizing guide allows for 26×26 or 27×27 depending on the fabric. Different makers use slightly different rules, but 26×26 remains the safest default that works across nearly all covers. If you want the plush, overstuffed hotel look, go with 28×28.
References & Sources
- Chloe and Olive. “Pillow Insert Size Guide.” Recommends 26×26 inserts for 24×24 covers.
- Arianna Belle. “Insert Size Guide.” Lists 26×26 or 27×27 options, noting larger sizes suit thicker fabrics.
- Mississippi Stitches. “New Sizing Guidelines.” Confirms 26×26 as the standard fill for 24×24 covers.