Pillow Insert Size Guide | What Size Insert for My Pillow Cover?

Pillow Insert Size Guide — What Size Insert for My Pillow Cover?

The most common question we hear at The Fluff Haus is: "What size pillow insert should I buy for my cover?" The answer makes the difference between a pillow that looks flat and sad versus one that looks plump, full, and professionally styled. Here's our expert guide, based on thousands of pillows we've handcrafted in Hickory, North Carolina.

For most pillow covers, order an insert that is 2 inches larger than the cover in both width and height. This creates the full, rounded look you see in design magazines and styled homes. The extra fill compresses slightly when inserted into the cover, eliminating gaps and creating a plump, inviting pillow.

When to Adjust

  • Structured or stiff covers (thick fabric, tight zipper): Go 1 inch over. Example: 20×20 cover → 21×21 insert. Too much overstuffing can stress zippers and seams on rigid covers.
  • Standard cotton or linen covers: Go 2 inches over. This is the sweet spot for most pillow covers. Example: 20×20 cover → 22×22 insert.
  • Loose, slouchy, or soft knit covers: Go 2–3 inches over. These fabrics have more give and need more fill to look full. Example: 20×20 cover → 22×22 or even 23×23 insert.
Pillow Cover Size Recommended Insert (Standard Look) Recommended Insert (Extra Full)
12×12 14×14 15×15
14×14 16×16 17×17
16×16 18×18 19×19
18×18 20×20 21×21
20×20 22×22 23×23
22×22 24×24 25×25
24×24 26×26 27×27
26×26 (Euro) 28×28 29×29

Lumbar / Rectangular Pillow Covers

Cover Size Recommended Insert
12×16 14×18
12×18 14×20
12×20 14×22
12×24 14×26
14×20 16×22
14×24 16×26
14×36 16×38

No problem. The Fluff Haus makes custom pillow inserts in any size — we're not limited to standard dimensions. If your cover is 13×19 or 17×23 or any other non-standard size, we'll make an insert to match (plus your preferred overfill). Every insert is handcrafted to order in Hickory, North Carolina.

All Fluff Haus pillow inserts use our premium hypoallergenic faux down alternative fill. It's a polyester microfiber that mimics the loft, softness, and squishability of natural down — without allergens, without feather poke-through, and without the flat spots that cheap polyester fill develops. It's machine washable and indoor/outdoor safe.

For more about our fill and how it compares to natural down, see our Down vs. Down Alternative Guide.

Shop our full collection of custom pillow inserts or contact us for custom sizes. Every insert is handcrafted and Made in USA by The Fluff Haus.

Related Resources

Sizing Guide Down vs Down Alternative Custom Sizes Shop Pillow Covers Shop Inserts