How to Make a Cushion Cover With a Zip (Beginner-Friendly, in cm)

Updated October 2026 · By Sam K, Fabrica Kraft

Quick answer: Cut one front square and two back rectangles. For a 45 cm cushion, cut the front at 48 × 48 cm and each back piece at 48 × 25.5 cm, using a 1.5 cm seam allowance. Sew the two back pieces together along their long edge, leaving a gap in the middle, and stitch a 35 cm zip into that gap. Open the zip partway, place the back on the front with right sides together, sew around all four edges, trim the corners and turn it right side out.

A zip cushion cover is one of the best first sewing projects. It's quick, it uses less than half a metre of fabric, and the zip means you can take the cover off to wash it. Putting the zip in the back, rather than along an edge, is the easiest method for beginners because you sew it into a straight seam. Here's how to do it, with exact cutting sizes.

What you'll need

• Fabric: about 0.5 m of medium- to heavy-weight fabric, such as cotton canvas, linen blend or furnishing fabric. Very thin fabric wrinkles and shows the zip.
• A zip: about 10 cm shorter than the cushion width (so a 35 cm zip for a 45 cm cushion).
• A cushion insert in the finished size
• Matching thread
• A sewing machine with a zipper foot
• Fabric scissors or a rotary cutter, pins, tailor's chalk and a ruler

Step 1: Cut your fabric

This chart uses a 1.5 cm seam allowance and a back-zip design. The back is made from two pieces so the zip can go across the middle.

The rule for any size: the front is the finished size plus 3 cm each way. Each back piece is the full width plus 3 cm, by half the height plus 3 cm.

Pattern tip: if your fabric has stripes or a large print, centre the design on the front piece before you cut, and line the stripes up across the back pieces.

Step 2: Neaten the edges

Zigzag or overlock along the long edge of each back piece where the zip will go. This stops the fabric fraying inside the cover. Linen and loosely woven fabrics fray quickly, so don't skip it.

Step 3: Sew the zip seam

1. Place the two back pieces right sides together, with the neatened edges lined up.
2. Lay the zip along the edge and mark where the zip teeth start and stop with chalk.
3. Sew from each end to your chalk marks with a normal stitch, and backstitch.
4. Between the marks, sew with the longest stitch your machine has. This is a temporary "basting" stitch that holds the seam closed while you fit the zip.
5. Press the seam open with an iron.

Step 4: Put in the zip

1. Turn the back piece over so the wrong side faces up.
2. Lay the zip face down over the seam, with the teeth exactly on the seam line. Pin or tack it in place.
3. Fit the zipper foot to your machine.
4. From the right side of the fabric, sew around the zip about 7 mm from the seam line, pivoting at the corners at each end. Go slowly around the zip pull.
5. Unpick the long basting stitches between your chalk marks. The zip should now open and close.

This method, used in many beginner tutorials including The Dreamstress's zip-back cushion guide, hides the zip neatly under the fabric folds.

Step 5: Sew the cover together

1. Open the zip about halfway. This is the step everyone forgets. If the zip is closed, you can't turn the cover right side out at the end.
2. Place the back on the front, right sides together. Trim the back so the edges match the front exactly.
3. Pin, then sew around all four sides with a 1.5 cm seam, pivoting at the corners.
4. Zigzag or overlock the raw edges.
5. Snip across each corner, close to the stitching but not through it. This gives you sharp corners.

Step 6: Turn, press and fill

Turn the cover right side out through the zip. Push the corners out gently with a knitting needle or chopstick. Press the seams, then fold the insert in half, slide it in, and let it open up inside.

Getting a plump, professional look

• Feather inserts: use an insert about 5 cm bigger than the cover (so a 50 cm insert in a 45 cm cover). This gives that full, "karate chop" look.
• Polyester inserts: the same size as the cover is usually fine, or 2 to 3 cm bigger for a fuller look.
• Press as you go. Pressing each seam makes a bigger difference than any other single tip.
• Add piping for a tailored edge. Sew it to the front piece before joining the back.

Common mistakes

DIY or made to measure?

Sewing your own is perfect for a few standard square cushions. It gets harder for unusual sizes, long bolsters, piped edges or covers that need to match your sofa or outdoor setting exactly. And if you want outdoor scatter cushions that won't fade in the Australian sun, the fabric matters as much as the sewing.

We make cushion covers to any size, with a zip, in Warwick, Sunbrella and velvet fabrics. You can order the cover on its own or with a micro-fibre fill. Browse our scatter cushions and outdoor cushions, velvet cushions, or custom cushion covers for seat and bench cushions. Shipping is free anywhere in Australia.

For outdoor styling ideas, see alfresco and pool cushion ideas.

Frequently asked questions

How much fabric do I need for a cushion cover?

About 0.5 m of standard-width fabric makes one 45 or 50 cm cover with a zip back. Buy extra if you need to match a pattern.

What size zip do I need for a cushion cover?

About 10 cm shorter than the width of the cushion. For a 45 cm cushion, use a 35 cm zip.

Should a cushion cover be smaller than the insert?

Usually, yes, for feather inserts: about 5 cm smaller. For polyester inserts, the same size or 2 to 3 cm smaller works well.

Can I make a cushion cover without a zip?

Yes. An envelope back, made from two overlapping back pieces, needs no zip. It's easier, but the opening can gape on a firm insert.

What is the best fabric for cushion covers?

Medium-weight furnishing fabrics, cotton canvas and linen blends are easiest to sew. For outdoor cushions, use a solution-dyed outdoor fabric so the colour lasts in the sun.

Sources

• The Dreamstress: How to make a simple zip-back cushion cover