Pillow Insert Size Guide
A pillow insert should be bigger than the finished cover, not the same size, or the corners go flat and empty.
Standard pillow insert sizes
| Common name | Size |
|---|---|
| Small square | 12" × 12" |
| Small square | 14" × 14" |
| Standard square | 16" × 16" |
| Standard square | 18" × 18" |
| Large square | 20" × 20" |
| Large square | 22" × 22" |
| Euro square | 24" × 24" (also 26×26) |
| Small lumbar | 12" × 20" |
| Standard lumbar | 14" × 24" |
| Body pillow | 20" × 54" |
Why the insert should be bigger than the cover
A cover sewn to the exact same dimensions as the insert comes out looking flat and a little deflated, with visibly empty corners. Sizing the insert about 2" larger than the finished cover in each direction compresses it slightly inside the cover, which is what gives a pillow its full, plump look.
When to match sizes exactly instead
A few situations call for a snugger, closer-to-exact fit: a tailored bolster or a minimalist, structured look where a slightly firmer, less rounded silhouette is the goal. For most decorative throw pillows, though, sizing up is what reads as "full" rather than "flat."
Down and down-alternative inserts compress more
A down or down-alternative insert compresses more readily than a firm foam one, so it can take a slightly bigger size-up (closer to 2–3") and still look full without straining the seams. Foam inserts hold their shape more rigidly, so keep the size-up closer to 1–2" to avoid an insert that won't quite fit inside the cover.
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