How to Measure for Pillow Cover Size? | Seam-To-Seam Method

Measure your pillow cover flat, empty, and inside out from seam to seam for the true size.

Getting the right pillow cover size starts before you shop. The fix for a baggy or overstuffed cover is simple: measure the cover the way manufacturers do. The proper technique takes under two minutes and works whether you are replacing a worn cover, sewing your own, or ordering a fresh insert for a fuller look. Skip the guesswork with this seam-to-seam method.

Measure Correctly: The Seam-To-Seam Method

Start by removing the insert from the cover. If you can take it out, turn the cover inside out. Lay it flat on a smooth surface and let it settle for a moment, smoothing out wrinkles with your hands. Use a flexible tape measure — a stiff ruler will not hug the curved seams.

Measure the width from the left seam to the right seam. Then measure the length from the top seam to the bottom seam. Record both numbers in inches. These seam-to-seam readings are what most manufacturers use when they list cover dimensions.

Why seam to seam? Measuring a stuffed pillow across the center compresses the fabric and skews the reading by an inch or more. The seams are the fixed points; the stuffing is not.

No Insert? Measure Still Works

If you cannot remove the insert — say, the cover is sewn shut — you can still get a usable number. Pinch the top corners and pull the seam as straight as possible against the tape measure. Add about 1/2 inch as an allowance for the compression the stuffing creates.

Some makers state their posted cover measurements are taken across the middle interior midpoints, not corner to corner at the edge. Corner-to-corner measuring can be off by 1–2 inches compared with the interior-seam method, so if you have ever ordered a cover that seemed slightly off, this is why.

For round, bolster, or kidney-shaped pillows, measure the widest width and height. If the pillow has a thick middle, also wrap the tape around its girth at the thickest point.

Compare Your Numbers To Standard Sizes

Once you have your cover’s flat measurements, match them against the standard pillow sizes below. Pillow dimensions are often rounded to the nearest whole inch, so your cover being about an inch off a listed size is normal, not a defect.

US, UK, and EU standards differ, so check the retailer’s chart rather than assuming a “standard” label means the same size everywhere. If your measured cover lands between sizes, size down for a snug fit or up for a softer drape. Most retailers suggest an insert the same size as the cover, but some recommend a slightly larger insert — about 1 inch larger for covers under 18 inches and 2 inches larger for bigger covers — for a fuller look.

Picking The Right Insert And Cover

Your flat cover measurement tells you the insert size to shop for. A 20 x 26-inch cover pairs with a standard insert for a classic feel, or a 20 x 28-inch super standard insert if you prefer a plumper look while still fitting the length. Match your cover’s width to the insert width for the cleanest result.

Fabric thickness and fill loft both affect how a cover fits once the insert is inside. A dense down insert makes a cover look fuller; a thin synthetic one lets it drape. Between sizes, pick the smaller cover for a snug fit that resists shift.

Before ordering, check the retailer’s own size chart. Some brands cut generously, others run a half-inch tight. When you are ready to shop, our roundup of the best bed pillow covers tested compares options that hold up to washing and keep their shape.