Measure your cushion and cut fabric pieces
Start by measuring your cushion on all four sides. Measure the length, width, and depth — the depth is the thickness of the cushion itself. Write these numbers down. A 24-inch-wide by 24-inch-deep by 5-inch-thick cushion needs two pieces of fabric that are 24 by 24 inches (front and back), plus four side strips that are 24 by 5 inches and two strips that are 24 by 5 inches.
Add one half-inch to every measurement for seam allowance — the space where two pieces of fabric join. So a 24-by-24-inch front piece becomes 25-by-25 inches when you cut it. Lay your fabric on a flat surface, use a ruler or measuring tape, and mark the cutting lines with tailor's chalk or a fabric pencil. Cut slowly and keep the scissors straight so edges stay even.
If your fabric has a pattern or direction (like stripes or a nap), lay all pieces in the same direction before cutting. This prevents the cover from looking backwards on one side. For patterned fabric, you may need extra yardage to match the pattern across seams.
Key Takeaways
- Measure your cushion's length, width, and depth, then add half an inch to each measurement for seam allowance before cutting fabric.
- Sew the four side strips to the front piece first, then attach the back piece last so you can insert the cushion before closing the final seam.
- Use a straight stitch on a sewing machine set to medium speed, and backstitch at the start and end of each seam to lock the thread.
- Leave one side seam partially open (about 12 inches) so you can turn the cover right-side-out and slide the cushion inside.
- Close the opening with a ladder stitch by hand, which creates an invisible seam that looks professionally finished.
Sew the side strips to the front piece
Place your front fabric piece on a flat surface with the right side (the pretty side) facing up. Take one side strip and place it right-side-down on top of the front piece, lining up one long edge. Pin the two pieces together along that edge, spacing pins about 4 inches apart. The pins hold the fabric steady while you sew.
Sit at your sewing machine and thread it with thread that matches your fabric color. Set the machine to a straight stitch and a medium speed. Place the pinned edge under the presser foot (the metal piece that holds fabric down) and lower the foot. Backstitch three or four stitches to lock the thread, then sew forward along the pinned edge at a steady pace. Remove pins as you reach them — never sew over a pin. When you reach the end, backstitch again and cut the thread.
Repeat this step for the other three side strips, sewing each one to an adjacent edge of the front piece. You now have a cross shape: the front piece in the middle with four strips extending outward.
Attach the back piece and leave an opening
Fold the four side strips up so they stand perpendicular to the front piece, like the sides of a box. The right sides of the strips should face outward. Fold the corners of the strips so they meet at right angles — this is where the side strips will eventually seam to each other.
Place the back fabric piece on top, right-side-down, so it aligns with the outer edges of the four side strips. Pin around all four edges. Before you sew, decide which side will have the opening. You will leave about 12 inches of this seam unsewn so you can turn the cover right-side-out and insert the cushion.
Sew three complete sides, backstitching at the start and end of each. On the fourth side, sew from one corner about 6 inches along the edge, backstitch, cut the thread, and stop. Skip the middle 12 inches, then restart the machine 6 inches from the other corner and sew to the end. This leaves a 12-inch gap in the middle of one side.
Sew the corner seams where side strips meet
Turn the cover right-side-out through the 12-inch opening. Use your fingers to gently push the corners out so they are sharp and square. The seams you sewed earlier are now on the inside, and the pretty side of the fabric faces outward.
Reach inside the cover and find where two side strips meet at a corner. Fold the cover so these two strips lie flat against each other, right-sides-together. Pin along the edge where they meet. Sew a seam about half an inch from the edge, backstitching at the start and end. Repeat at all four corners. These seams box out the cushion so it sits properly inside.
Insert the cushion and close the opening with a ladder stitch
Slide your cushion into the cover through the 12-inch opening. Adjust it so it sits evenly and the corners fill out. Fold the raw edges of the opening inward by half an inch and pin them together so the fold lines meet in the middle.
Thread a needle with thread that matches your fabric. Tie a knot at the end of the thread. Bring the needle up through the fold on one side of the opening, coming out right at the fold line. Cross to the opposite side and insert the needle directly across from where you came out, going through the fold. Slide the needle inside the fold for about half an inch, then come back out. Cross back to the first side and repeat — you are creating a ladder pattern that locks the two folded edges together.
Work slowly and keep your stitches small (about a quarter inch) and tight. Every few stitches, pull the thread gently to close the gap. When you reach the end of the opening, tie off the thread inside the fold so the knot is hidden. The finished seam should be nearly invisible from the outside.
Press seams and finish edges
Use an iron on a medium heat setting to press all the seams flat. Press from the inside first, then flip and press the outside. This makes the cover look crisp and professional. If your fabric frays easily (like linen or cotton), you can finish the raw edges inside the cover by sewing a zigzag stitch along each seam allowance, or by hand-stitching a whip stitch along the edges.
For a cushion cover that will be removed and washed often, finishing the edges prevents them from coming apart over time. If your fabric is a tight weave that does not fray much, this step is optional.
Frequently Asked Questions
What type of fabric works best for couch cushion covers?
Cotton, linen, and cotton blends are durable and straightforward to sew. Avoid stretchy fabrics like jersey or spandex unless you are experienced — they slip under the presser foot and create uneven seams. Upholstery-weight fabric lasts longer than quilting cotton but is thicker and harder to sew by hand.
Can I add a zipper instead of sewing it closed?
Yes. Install a zipper along one side seam before you attach the back piece. Sew the zipper to the side strip and back piece using a zipper foot on your machine. This makes the cover removable for washing, though zippers are more visible than a ladder stitch and add cost.
How much fabric do I need to buy?
Measure your cushion and add one inch to the length and width (half inch on each side for seam allowance). For a 24-by-24-inch cushion, buy fabric that is at least 25 by 25 inches for the front and back, plus extra for the four side strips. Most fabric stores sell by the yard, so ask the staff to help you calculate yardage based on your cushion size.
What if my seams are crooked or uneven?
Crooked seams are normal when learning. They do not affect how the cover fits or functions. If a seam is very far off and the cover does not fit the cushion, you can carefully cut the seam open with a seam ripper, adjust the fabric, and sew again. Practice on a scrap piece first.
Do I need a serger or special machine?
No. A basic sewing machine with a straight stitch is all you need. A serger finishes edges more neatly but is not required. If you do not own a machine, many fabric stores and community centers offer sewing classes and machine access for a small fee.