Measure your cushion and cut fabric pieces
Start by measuring your cushion in three directions: length, width, and thickness. Write these numbers down. For a cushion that is 16 inches long, 16 inches wide, and 4 inches thick, you will cut two pieces of fabric 18 inches by 18 inches (that is your length and width plus 1 inch on each side for seam allowance). You will also cut four strips for the sides, each one 6 inches tall and as long as the cushion's length or width—so four strips that are 6 inches by 18 inches.
Lay your fabric on a flat surface and use a ruler or measuring tape to mark these measurements with tailor's chalk or a fabric pen. Cut slowly and straight along your marks. If your fabric has a pattern or nap (like velvet, where the pile runs one direction), cut all pieces in the same direction so they match when sewn together.
Key Takeaways
- Measure your cushion's length, width, and thickness, then add 1 inch seam allowance to the top and bottom pieces and 1 inch total to the side strips.
- Pin all four side strips to the top piece first, then sew them with a straight stitch at a quarter-inch seam allowance, backstitching at the start and end of each seam.
- Attach the bottom piece the same way, but leave one side partially open so you can turn the cover right-side out and insert the cushion.
- Turn the cover right-side out through the opening, press the seams flat with an iron, insert the cushion, and hand-stitch the opening closed with a ladder stitch.
- A sewing machine makes this project faster, but you can hand-sew the entire cover using a backstitch if you do not have access to one.
Pin and sew the side strips to the top piece
Lay your top fabric piece flat, right-side up. Take one of your four side strips and place it right-side down along one edge of the top piece, so the raw edges line up. Pin every 2 to 3 inches along that edge, pushing the pin through both layers. The pins hold the fabric steady while you sew.
If you are using a sewing machine, set it to a straight stitch with a stitch length of 2.5 millimeters. Position the fabric under the presser foot so the needle will sew a quarter-inch from the edge. Backstitch (sew backward) three or four stitches at the start, then sew forward along the pinned edge. When you reach the corner, backstitch again and remove the fabric. Repeat this step for all four sides, pinning and sewing one strip at a time.
If you are hand-sewing, thread a needle and tie a knot at the end. Push the needle through both layers a quarter-inch from the edge, then bring it back up a quarter-inch away. Repeat this backstitch along the entire edge, keeping your stitches small and even. This takes longer but produces the same result.
Attach the bottom piece, leaving an opening for turning
Once all four side strips are sewn to the top piece, you will attach the bottom piece the same way. Lay the cover flat with the side strips pointing outward. Place your bottom fabric piece right-side down on top, so raw edges line up all around. Pin along three complete sides and most of the fourth side, but leave a 6-inch gap unpinned on one edge—this is your turning opening.
Sew around the pinned edges using the same quarter-inch seam allowance and backstitch method. Stop when you reach the gap, backstitch, and remove the fabric. Do not sew the gap closed yet; you need this opening to turn the cover right-side out and insert the cushion.
Turn the cover right-side out and press the seams
Reach through the 6-inch opening and grab the top piece of fabric from the inside. Pull gently and steadily until the entire cover turns inside-out through the opening. This takes patience—go slowly to avoid tearing the seams. Once it is turned, use your fingers to push the corners and edges out so they are crisp and square.
Lay the cover flat on an ironing board and set your iron to the heat setting for your fabric type (check the fabric care label). Press along all the seams, paying special attention to the corners and the edges around the opening. Pressing flattens the seams and makes the finished cover look neat. Let the cover cool for a minute before moving it.
Insert the cushion and close the opening
Slide your cushion into the cover through the 6-inch opening. Push it all the way in so it sits evenly inside. The cover should fit snugly around the cushion with no wrinkles or bunching.
Close the opening with a ladder stitch, also called an invisible stitch. Thread a needle and tie a knot. Bring the needle up through the fold of fabric on one side of the opening, then across into the fold on the opposite side. Slide the needle inside the fold for about a quarter-inch, then bring it back out and cross to the other side. Repeat this zigzag pattern along the entire opening. The thread runs inside the fold and is hidden from view. When you reach the end, tie a knot inside the fold and trim the thread.
Common mistakes to avoid
The most common error is cutting pieces that are too small. If your seam allowance is too narrow or your measurements do not account for the cushion's thickness, the cover will be tight and hard to close. Always add at least 1 inch to your measurements before cutting.
Another frequent problem is sewing the side strips in the wrong order or at the wrong angle. Sew them one at a time, always pinning first and checking that the raw edges line up before you sew. If a strip is sewn crooked, the corners will not meet evenly and the cover will look lopsided.
Leaving the opening too small makes it nearly impossible to turn the cover and insert the cushion. A 6-inch opening is the minimum for most seat cushions; for larger cushions, make it 8 inches. You can always make the opening larger if you get stuck.
Hand-sewing versus machine-sewing
A sewing machine completes this project in 45 minutes to an hour. Hand-sewing takes 2 to 3 hours because each stitch is made individually. A machine also produces more consistent, stronger seams, especially along the side strips where stress is greatest.
Hand-sewing is a good choice if you do not have access to a machine, if you enjoy the meditative pace, or if your fabric is delicate and might snag in a machine. Use a backstitch for all seams except the ladder stitch closing—a backstitch is strong enough to hold the cover together through regular use. A running stitch (the simplest hand stitch) is too weak for a cushion cover that will be sat on.
Frequently Asked Questions
What type of fabric works best for a seat cushion cover?
Cotton, linen, and cotton blends are durable and straightforward to sew. Avoid very stretchy fabrics like jersey or spandex unless you have experience—they slip under the needle and are hard to control. Upholstery fabric, denim, and canvas are all excellent choices. Check that your fabric is sturdy enough that you cannot easily tear it by hand.
Do I need a sewing machine to make a cushion cover?
No. You can hand-sew the entire cover using a backstitch, which is strong and reliable. It takes longer—plan for 2 to 3 hours instead of 45 minutes—but the result is just as durable. A needle, thread, and scissors are all you need.
What if my cushion is an odd shape, like round or hexagonal?
Measure the longest point across the shape and add 1 inch for seam allowance. Cut your top and bottom pieces to that size, then cut side strips to fit around the perimeter. You may need more than four strips for a round cushion—measure the distance around the edge and divide by the width of your strips to find out how many you need.
Can I add a zipper instead of hand-stitching the opening closed?
Yes. Before you sew the bottom piece on, insert a zipper along the opening edge. Pin the zipper between the top and bottom pieces so the teeth face inward, then sew it in place using a zipper foot on your machine (or by hand with small stitches). This makes the cover removable for washing, though it adds 15 to 20 minutes to the project.
How do I keep the cushion from shifting inside the cover?
Once the cover is closed, you can hand-stitch through all layers at the corners to anchor the cushion in place. Push your needle through the cover and into the cushion about a quarter-inch, then back out and tie a knot. This prevents the cushion from bunching to one side during use.