How to Replace an Elastic Waistband

For exposed elastic, you are going to cut a strip of elastic to the size of your waist. To do this, wrap the elastic around where you would like the pants to sit and pull it so it is snug. You want it to be tight but not constricting. Cut the elastic strip.

Cut the old elastic out of your pants. You can cut just below where the old seam is or if you are worried about fraying, you can cut just above it.

Pin the new elastic to the sweatpants with about a half inch of fabric overlapping. I am putting my elastic on the outside of the pants, but if you want you can fold down the edge of your pants slightly and put the elastic on the inside. You want to make sure the elastic is stretched out, so pin at the beginning, end and then at the half way point on the pants.

Start sewing the elastic with a zig-zag, overcasting, or joining stitch. Wherever you start, when you get back to that place, sew a couple of stitches overlapping because you won’t be able to backstitch at the beginning. Also, sew the ends of the elastic together.

For hidden elastic waistbands, you are going to cut a strip of elastic to the size of your waist the same way as before.

Find where the old elastic is sewn into the pants and cut a hole large enough to take out the old elastic and insert the new. You may need a seam ripper to detach the elastic from the pants. Be careful to not rip through the pants while removing the elastic.

Attach a safety pin to one end of the new elastic. Insert it into the hole and start pushing the elastic through. Make sure the other end of the elastic stays outside of the pants for now. When you get the safety pin through to the other side, attach the two ends together with a pin.

Using a needle and thread, sew the two ends together, make this as flat as possible or else you will be able to feel the seam. You can also use a zig zag stitch to sew the ends together. Then put the elastic inside the hole and sew it shut. And now your sweatpants are good as new.