Measure your cushion and cut fabric pieces

Start by measuring your cushion on all sides. Measure the length, width, and depth — if your cushion is 24 inches long, 18 inches wide, and 5 inches thick, write those numbers down. You will cut two main pieces (front and back) and four side strips (called gussets) that wrap around the edges.

For the front and back pieces, add 1 inch to both the length and width for seam allowance. So a 24-by-18 cushion becomes two pieces cut at 25 by 19 inches. For the four gussets, cut strips that are 6 inches wide (the 5-inch depth plus 1 inch for seam allowance) and as long as each side of your cushion plus 1 inch. Two strips will be 25 inches long, and two will be 19 inches long. Cut all pieces from your fabric using sharp scissors or a rotary cutter and ruler.

Key Takeaways

  • Measure your cushion's length, width, and depth, then add seam allowance before cutting fabric to avoid covers that are too tight or too loose.
  • Sew the four gusset strips to the front piece first, then attach the back piece last so you can leave one seam partially open for turning and stuffing.
  • Use a 1/2-inch seam allowance throughout, backstitch at the start and end of each seam, and press seams flat with an iron as you go to keep edges neat.
  • Turn the cover right-side out through the opening, push corners out with a blunt tool, and slip-stitch the opening closed by hand after inserting the cushion.

Attach the gusset strips to the front piece

Lay your front piece flat on a table with the right side (the side you want showing) facing up. Take one of the longer gusset strips and place it right-side down along one long edge of the front piece, so the raw edges line up. Pin the gusset to the front piece every 3 to 4 inches along that edge.

Sew the gusset to the front piece using a 1/2-inch seam allowance. Start at one corner, backstitch (sew backward a few stitches) to lock the thread, then sew forward along the entire edge. When you reach the corner, backstitch again and cut the thread. Repeat this step for all four gussets, sewing them one at a time around all four sides of the front piece. After each seam, press it flat with an iron to keep the edges crisp.

Sew the gussets together at the corners

The four gusset strips now form a frame around your front piece, but they overlap at the corners. Fold the cover so two adjacent gussets meet at a right angle, right sides together. Pin them and sew along the corner seam using a 1/2-inch seam allowance. Backstitch at the start and end. Repeat for all four corners, pressing each seam flat as you finish.

Your front piece should now be completely surrounded by gussets that form a box shape. The raw edges of the gussets should all face outward, ready to attach the back piece.

Attach the back piece, leaving an opening

Pin the back piece to the outer edges of the gussets, right sides together. The back piece should line up with all four gussets around the perimeter. Before you sew, decide which side will have your opening — usually the bottom or back of the cushion. Sew three complete sides with a 1/2-inch seam allowance, backstitching at corners and at the start and end of each seam.

On the fourth side (your opening side), sew only halfway across. Start at one corner, sew to the middle of that side, backstitch, and cut the thread. Leave the remaining half unsewn — this opening is where you will turn the cover right-side out and insert the cushion. Press all seams flat with an iron.

Turn the cover right-side out and shape the corners

Reach through the opening and grab the front piece from inside. Pull the entire cover through the opening so the right side (the pretty side) is now facing outward. The seams should be hidden inside. Take your time and work gently so you do not tear the fabric.

Use a blunt tool like a wooden spoon handle or a chopstick to push out each corner from the inside, creating sharp, clean corners. Push gently into each corner until the point is fully extended. Press the entire cover with an iron, paying special attention to the seams and the opening edges. Fold the raw edges of the opening inward by 1/2 inch and press them flat.

Insert the cushion and close the opening

Slide your cushion into the cover through the opening. Adjust it so it sits evenly inside and the corners are filled out. The cushion should feel snug but not so tight that the fabric strains.

Close the opening using a slip stitch, also called a ladder stitch. 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 of fabric on one side of the opening, so the knot stays hidden inside the fold. Cross to the opposite side and insert the needle directly into the fold of that side. Slide the needle inside the fold for about 1/2 inch, then bring it back out. Cross back to the first side and repeat, moving along the opening. The stitches should be small and close together — about 1/4 inch apart. When you reach the end, tie off the thread inside the fold and trim the excess. The opening should now be invisible.

Frequently Asked Questions

What fabric should I use for a sofa cushion cover?

Use a durable, tightly woven fabric like cotton canvas, linen, or upholstery-weight cotton. Avoid thin fabrics like quilting cotton or jersey knit, which will not hold up to regular use. If your cushion will get heavy wear, consider a performance fabric designed for upholstery.

Can I use a sewing machine for the whole project?

Yes, except for closing the opening. A sewing machine is faster and stronger for all the seams that hold the cover together. The slip stitch at the opening must be done by hand so it is invisible from the outside.

What if my corners come out lumpy or uneven?

Lumpy corners usually mean the seam allowance is too wide at the corner or the fabric was not pressed flat. When you turn the cover right-side out, use your blunt tool to gently work the corner into shape. If the problem is severe, you can unpick that corner seam, trim the excess fabric, and sew it again.

Do I need a pattern to make a cushion cover?

No. A pattern is just a guide for cutting and sewing in the right order. Since you are measuring your own cushion, you are creating a custom pattern as you measure. Write down your measurements and follow the steps in order, and your cover will fit.

How much fabric do I need to buy?

Add up the length and width of your front piece, then add the depth and seam allowance for all four gussets. For a 24-by-18-by-5 cushion, you need roughly 2 to 2.5 yards of 54-inch-wide fabric, depending on how you arrange your pieces. Ask the fabric store staff to help you estimate if you are unsure.