Hemming curtains on a sewing machine takes about 30 minutes per panel once you measure and pin

A sewing machine hem is a straight line of stitches that folds the fabric edge under twice and locks it in place. You measure how much fabric to fold, pin it, and run the folded edge under the presser foot. The machine does the work; you guide the fabric straight. Most home machines handle curtain fabric without adjustment, and the finished hem lasts through years of washing and opening and closing.

The whole process is: measure the finished length you want, mark where to cut, fold the raw edge under a quarter inch, fold it under again a half inch to an inch, pin the fold, sew a straight line close to the inner fold, and press with an iron. A single curtain panel takes 20 to 30 minutes the first time you do it. The second panel is faster because you know the rhythm.

Key Takeaways

  • Measure from the top of the curtain to where you want the hem to end, then add 1.5 inches for the fold-under, and cut the fabric there.
  • Fold the raw edge under a quarter inch, then fold it under again a half inch to one inch, and pin every two inches along the fold.
  • Sew with a straight stitch about an eighth inch from the inner fold, using a medium stitch length (2.0 to 2.5 on most machines) and matching thread.
  • Press the finished hem flat with an iron on a medium setting to set the stitches and remove wrinkles.
  • Test the hem by hand-washing a corner or checking the machine's manual if your curtain fabric is delicate or has a special finish.

Measure and mark the hem length before cutting

Hang the curtain panel on the rod or lay it flat on a table with the top edge aligned straight. Measure down from the top to where you want the hem to end—usually one-quarter to one-half inch above the floor or windowsill, depending on your style. Write this measurement down. Add 1.5 inches to that number (this is the fabric you will fold under), and measure down that total distance from the top. Mark a line across the curtain with tailor's chalk or a fabric pencil.

Cut along the marked line with sharp fabric scissors. A dull blade will pull the threads and create a ragged edge that is harder to fold neatly. If the curtain is very long or heavy, have someone hold the other end so the fabric does not drag on the floor while you cut. Trim any loose threads from the cut edge with scissors before you fold.

Fold and pin the hem in two stages

Lay the curtain panel flat on a table or ironing board with the wrong side (the back) facing up. Fold the raw edge up toward the back of the fabric by a quarter inch. Use your fingers or a ruler to keep the fold straight and even. Press the fold flat with your hand or an iron set to low heat—this crease helps the second fold stay in place.

Fold the edge up again, this time by a half inch to one inch (most people use three-quarters inch). The raw edge is now hidden inside the fold. Press this fold flat as well. Pin the fold every two inches along the entire length, placing pins parallel to the fold so they do not get in the way of the presser foot. Step back and look at the fold from the front of the curtain to make sure it is straight and even.

Thread the machine and test the tension

Wind a bobbin with thread that matches the curtain fabric—white for white curtains, cream for cream, and so on. If the thread color is not a perfect match, choose a shade slightly darker rather than lighter; it is less visible in the finished seam. Insert the bobbin into the bobbin case and thread the top of the machine according to your machine's manual. Most machines have a diagram printed on the body showing the path the thread takes.

Set the machine to a straight stitch and adjust the stitch length to 2.0 to 2.5 millimeters (medium length). Test the tension on a scrap of folded curtain fabric before you sew the actual hem. Sew a short line and look at both sides—the stitches should look the same on the front and back, with no loops or loose threads. If the top thread is too tight, loosen the top tension dial slightly; if the bobbin thread shows on top, tighten it. Refer to your manual if you are unsure how to adjust tension.

Sew the hem with a straight, even line

Position the curtain panel under the presser foot so the needle will pierce the fabric about an eighth inch from the inner fold (the fold closest to the body of the machine). Lower the presser foot. Sew forward slowly, guiding the fold straight under the foot. Keep your hands relaxed and let the machine pull the fabric; do not push or pull hard, or the stitches will bunch. Sew the entire length of the hem without stopping.

When you reach the end, raise the presser foot and pull the curtain toward you to cut the thread. Leave a two-inch tail of thread on both the top and bobbin side; trim the excess with scissors. If you need to sew a second line of stitches for strength (common on heavy fabrics), reposition the curtain and sew a second line a quarter inch closer to the outer fold. Most home curtains need only one line of stitching.

Press the finished hem to set the stitches

Lay the curtain flat on an ironing board with the hemmed edge facing up. Set the iron to a medium heat setting appropriate for your fabric—check the curtain's care label if it has one. Press the hem gently, moving the iron in the direction of the fold, not back and forth. The heat sets the stitches and removes wrinkles from the fold. Do not press so hard that you flatten the fabric; let the weight of the iron do the work.

Flip the curtain over and press the back side as well. This ensures the fold is flat and the stitches are find. Let the curtain cool for a minute before you move it. Hang the curtain back on the rod and step back to check that the hem hangs straight and the length is even.

Common mistakes and how to avoid them

The most common mistake is folding the hem too narrow. A fold narrower than half an inch is hard to sew straight and may not hold up through repeated washing. Measure twice and fold generously—three-quarters inch is a safe choice for most curtains. Another mistake is sewing too close to the outer fold, which can cause the raw edge to show or fray. Sew an eighth inch from the inner fold, not the outer one.

Skipping the first quarter-inch fold is also common. That first small fold hides the raw edge completely, so the hem looks finished on both sides. If you skip it and fold only once, the raw edge will be visible and will fray in the wash. Finally, do not sew with the presser foot pressure set too high, or the fabric will bunch and the stitches will be uneven. Most machines have a dial or lever to adjust presser foot pressure; set it to the lowest setting that still holds the fabric in place.

Frequently Asked Questions

Can I hem curtains made of delicate fabric like linen or silk?

Yes, but test a corner first. Fold and sew a small section at the edge of the curtain, then wash it by hand to see how the fabric and stitches respond. Use a needle one size smaller than you would for cotton, reduce the presser foot pressure, and use a stitch length of 2.0 millimeters. If the fabric puckers or the stitches pull, hand-sewing with a slip stitch may work better.

What if my curtain is too wide to fit under the presser foot?

Fold the curtain lengthwise so the hem edge is on the outside, and roll it loosely. Unroll just enough to fit under the foot, sew a section, then unroll more and continue. The rolled fabric will not interfere with the presser foot. Take your time and keep the fold straight as you unroll.

Do I need to use a special presser foot for hemming?

No. A standard all-purpose presser foot works fine for most curtain hems. If your machine has a walking foot (which feeds fabric evenly from top and bottom), it can help prevent puckering on heavy fabrics, but it is not required.

How do I fix a crooked hem after I have already sewn it?

Use a seam ripper to cut and remove the stitches, then re-fold and re-sew. Seam rippers are inexpensive and come with most machines. Slide the small hook under a stitch, lift it, and cut with the blade. Work your way along the seam. Once the stitches are out, press the fabric flat with an iron to remove the old crease, then fold and sew again.

Can I hem curtains without pinning them first?

You can, but pinning takes only a few minutes and makes the sewing much easier and straighter. Pins hold the fold in place so your hands are free to guide the fabric smoothly. Without pins, the fold can shift as you sew, and the hem line will be wavy. For your first curtain, pinning is worth the extra time.