The insert dimensions typically measure 2" larger than the pillow cover dimensions. Having a slightly bigger insert gives the pillow a more desirable shape. The following chart outlines the insert dimensions relative to the pillow cover.
| Pillow Cover Dimensions | Pillow Insert Dimensions |
| 12" x 24" or 13" x 24" | 15" x 26" |
| 14" x 22" | 16" x 24" |
| 14" x 36" | 16" x 38" |
| 14" x 40" | 16" x 42" |
| 20" x 20" | 22" x 22" |
| 22" x 22" | 24" x 24" |
| 24" x 24" | 26" x 26" |
| 5" x 20" | 6" x 22" |
| 15" | 18" |
| 13" x 20" | 15" x 22" |
| 12" x 22" or 12" x 20" | 14" x 24" |
| 14" x 20" | 16" x 22" |
| 6" x 53" | 6" x 56" |