Sewing elastic by hand or machine takes about 15 minutes once you have the right supplies
You can attach elastic to fabric using either a needle and thread or a sewing machine. The hand-sewing method works best for small projects, repairs, and waistbands on underwear or pajamas. Machine sewing is faster and stronger, making it the better choice for swimwear, activewear, and anything that gets heavy use. Both methods produce a finished edge that holds the elastic in place without bunching or rolling.
The key difference is that hand sewing creates a flexible seam that moves with the elastic, while machine sewing locks the elastic down with a continuous line of stitches. Neither method is difficult—you just need to know which stitch to use and how to position the elastic so it doesn't twist as you work.
Key Takeaways
- Hand sewing works for small elastic repairs and takes a needle, thread, and about 15 minutes; machine sewing is faster and stronger for garments that stretch.
- Measure and mark where the elastic will go before you start, and pin it in place so it stays flat and doesn't twist as you sew.
- A backstitch by hand or a straight stitch on a machine both hold elastic securely; use thread that matches your fabric or elastic.
- Overlap the elastic ends by half an inch before sewing them together, then sew the elastic to the fabric so the seam is hidden inside the fold.
What you need before you start
Gather these supplies: elastic (the width depends on your project—quarter-inch for lightweight fabrics, half-inch for waistbands), needle (size 70/10 or 80/12 for hand sewing), thread that matches your fabric or elastic, pins, scissors, and a measuring tape. If you are using a sewing machine, thread it with the same color thread on top and in the bobbin.
Test your needle on a scrap of fabric first. If the needle leaves holes that are too large or skips stitches, switch to a fresh needle—a dull needle is the most common reason elastic seams fail. For machine sewing, a ballpoint needle (size 75/11) works better than a sharp needle because it slides between fabric threads instead of piercing them, which reduces puckering.
Measuring and pinning the elastic in place
Measure around the opening where the elastic will go—the waist of a pair of shorts, the leg opening of a swimsuit, or the cuff of a sleeve. Subtract half an inch from that measurement and cut your elastic to that length. The half-inch difference creates tension so the elastic pulls the fabric snug without bunching.
Divide the elastic and the fabric opening into four equal sections. Mark each section with a pin on both the elastic and the fabric. Pin the elastic to the wrong side of the fabric (the inside), matching the marks so the elastic is evenly distributed. The elastic should lie flat against the fabric with no twists. If the elastic is curling or folding, unpin that section and smooth it out before pinning again.
Hand sewing elastic with a backstitch
Thread your needle and tie a knot at the end. Start at one of your marked sections and push the needle through both the elastic and the fabric from the back. Bring the needle up through the fabric about one-eighth inch ahead of where you started. Push the needle back down through the same hole you just came out of, then forward again one-eighth inch ahead. This is a backstitch—each stitch overlaps the one before it, creating a strong seam.
Work your way around the elastic, keeping your stitches small and even. The smaller your stitches, the stronger the seam. When you reach the end, tie off the thread on the inside of the fabric with a knot. Trim the thread close to the knot. If the elastic ends need to be joined, overlap them by half an inch and sew them together with a few stitches before you attach the elastic to the fabric.
Machine sewing elastic with a straight stitch
Set your machine to a straight stitch with a stitch length of 2.5 to 3 millimeters. Place the fabric under the presser foot with the elastic facing up. Align the needle so it will sew through the middle of the elastic, about one-eighth inch from the edge. Sew slowly and keep tension on the elastic with your fingers as you feed it under the presser foot—this prevents puckering and keeps the stitches even.
Stop every few inches and lift the presser foot to check that the elastic is still flat and not twisting. If it has twisted, unpin that section, straighten it, and continue. When you reach the end, backstitch a few stitches to lock the thread. Trim the thread ends close to the seam. If you are joining elastic ends, overlap them and sew them together with a short zigzag stitch before attaching the elastic to the fabric.
Finishing the seam so it does not show
Once the elastic is sewn to the fabric, fold the elastic and the seam allowance to the inside of the garment so the stitches are hidden. Pin the folded edge in place. If you are hand sewing, use a whip stitch to close the fold: bring the needle up through the fold, then push it straight across into the fabric just below the fold, slide it along inside the fabric for one-eighth inch, and come back up through the fold. Repeat all the way around.
If you are machine sewing, use a straight stitch or a narrow zigzag to sew the folded edge down, stitching as close to the fold as you can. This second line of stitching locks the elastic in place and prevents it from rolling or shifting when the garment is washed and worn. Press the seam flat with an iron on low heat once you are done.
Common mistakes and how to avoid them
The most common mistake is sewing the elastic too tight, which creates bunching and makes the garment uncomfortable. Remember to subtract half an inch from your measurement—that is enough tension. Another mistake is letting the elastic twist as you sew. Stop every few inches to check that it is lying flat, and pin it more densely if it keeps twisting.
Skipped stitches usually mean your needle is dull or too small for the fabric. Replace the needle and try again on a scrap. If the elastic is rolling after you finish, you did not fold and stitch the seam allowance down far enough. Go back and add a second line of stitching closer to the fold. Puckering on machine-sewn seams happens when you do not keep tension on the elastic as it feeds under the presser foot—slow down and hold the elastic gently with both hands.
Frequently Asked Questions
Can I sew elastic on the right side of the fabric instead of the wrong side?
Yes, but it will show. This works for decorative elastic on swimwear or activewear where the stitching is part of the design. Sew it the same way, but use thread that matches your elastic or contrasts intentionally. If you want the seam hidden, always sew on the wrong side and fold the seam allowance to the inside afterward.
What if my elastic is too wide for my needle?
Use a needle one size larger—go from a 70/10 to an 80/12 or 90/14. A needle that is too small for thick elastic will bend or break. Test on a scrap first. For very thick elastic, a machine sewing approach works better because the presser foot distributes pressure more evenly than a hand needle.
How do I join two pieces of elastic end to end?
Overlap the ends by half an inch and sew them together with a few stitches in an X pattern—this creates a strong joint that will not separate. Use thread that matches the elastic. Once the ends are joined, measure the loop and sew it to the fabric as described above.
Does the elastic need to be pre-washed before sewing?
Most modern elastic does not shrink, but if your elastic is vintage or very inexpensive, soak it in warm water for five minutes, lay it flat to dry, and measure it again before cutting. This prevents the elastic from shrinking after you sew it on and making the garment too tight.
Can I use a zigzag stitch instead of a straight stitch?
Yes. A zigzag stitch is actually better for elastic because it stretches with the fabric instead of breaking when the garment is pulled. Use a narrow zigzag (width 2 to 3, length 2.5) and sew down the middle of the elastic. This is especially useful for swimwear and activewear that gets a lot of stretch.