The Basic Process for Machine Hemming

A hem is a fold of fabric sewn down to finish an edge, usually at the bottom of pants, skirts, or sleeves. On a sewing machine, you fold the fabric up twice (to hide the raw edge inside), pin it in place, and sew a straight line close to the inner fold. The whole process takes 10 to 20 minutes per garment once you know the steps.

The standard approach works for most woven fabrics — cotton, linen, lightweight wool, and blends. You will measure how much fabric to fold, press it with an iron to set the crease, and then sew it down using a straight stitch and a standard presser foot. If you are hemming something you wear often, a machine-sewn hem lasts longer than a hand-sewn one because the thread runs through more fabric layers.

Key Takeaways

  • Measure the desired finished length from the hem fold to the waistband or shoulder, then add 1.5 inches and cut the garment to that length.
  • Fold the fabric up 0.75 inches, press it with an iron, then fold it up another 0.75 inches and press again to hide the raw edge inside the hem.
  • Pin the folded hem every 2 to 3 inches around the entire garment before sewing to keep it from shifting.
  • Sew with a straight stitch about 0.125 inches (one-eighth inch) from the inner fold, using a thread color that matches the fabric.
  • Test the hem on the garment before cutting thread and trimming loose ends, because small adjustments are easier to make before you finish.

Measure and Cut the Garment to Length

Put on the garment or have someone else wear it while you measure. Use a measuring tape or ruler to find the length you want the finished hem to be — for pants, this is usually where the pant leg hits the top of your shoe. Mark that spot with a pin or tailor's chalk on both the front and back of each leg.

Add 1.5 inches to your desired finished length, then cut the fabric straight across at that point. The extra 1.5 inches becomes the hem itself: 0.75 inches folds up once, then another 0.75 inches folds up again. If you cut too short, you cannot add fabric back. If you cut too long, you can always fold up more, but the hem will be thicker.

For sleeves, measure from the wrist bone to where you want the sleeve to end, add 1.5 inches, and cut straight across. For skirts, measure from the waistband down to your desired length, add 1.5 inches, and cut. Always cut in a straight line perpendicular to the grain of the fabric, or the hem will hang crooked.

Fold, Press, and Pin the Hem

Fold the raw edge of the fabric up 0.75 inches toward the inside of the garment. Use an iron set to the heat level safe for your fabric (check the garment tag) and press the fold flat. This crease helps the fabric stay folded while you sew and makes the final hem look crisp.

Fold the fabric up another 0.75 inches, so the raw edge is now hidden inside the double fold. Press this second fold flat as well. The inner fold — the one closest to the raw edge — is what you will sew along. Pin the hem every 2 to 3 inches all the way around the garment, pushing the pins perpendicular to the fold so they do not get in the way of the presser foot.

Check that the hem is even by measuring from the fold to the waistband or shoulder at several points. If one side is higher than the other, unfold, re-measure, and re-fold. Uneven hems are visible when you wear the garment, so take the time to get this step right.

Set Up the Sewing Machine and Thread

Thread your machine with thread that matches the color of the fabric as closely as possible. If you cannot find an exact match, choose a shade slightly darker rather than lighter — it is less visible. Use the same thread on both the top and in the bobbin.

Install a straight stitch presser foot (most machines come with this as the default foot). Set the stitch length to 2.0 to 2.5 millimeters — this is a standard length for hemming and creates a line of stitches that is strong but not so tight that it puckers the fabric. Test the tension on a scrap of the same fabric folded the same way before you start on the actual garment.

If your machine has a needle position dial, keep the needle centered. Some machines let you move the needle left or right, which can be useful for topstitching, but for a standard hem you want the needle in the middle of the presser foot.

Sew the Hem in a Straight Line

Position the garment under the presser foot so the needle will sew about 0.125 inches (one-eighth inch) from the inner fold of the hem. This distance is roughly the width of a dime. Sew slowly and steadily, keeping the fold aligned with the edge of the presser foot as a guide — most presser feet have a line marked on them that helps you stay straight.

Sew all the way around the garment, removing pins as you approach them. Do not sew over a pin — it can break the needle or damage the machine. When you reach the point where you started, overlap the stitches by about 0.5 inches, then backstitch to lock the thread and cut it.

If you are hemming pants with two legs, sew one leg completely, then move to the other. This prevents you from accidentally sewing the two legs together. For a skirt or dress, sew all the way around in one continuous line if possible, because a seam where you start and stop is slightly weaker than a continuous stitch.

Finish and Check the Hem

Put on the garment and look at the hem in a mirror. Check that it hangs evenly all the way around and that the stitches are not visible from the outside. If the hem is uneven or the stitches show, you can carefully remove the stitches with a seam ripper and re-sew. If the hem looks good, trim any loose thread ends with scissors.

Wash and dry the garment according to its care label before wearing it regularly. This sets the fabric and ensures the hem will not shift or pucker after the first wash. If the hem does shift slightly after washing, you can press it again with an iron to re-set the crease.

A machine-sewn hem is durable and will last through many washes if the thread color matches and the stitches are even. If you notice the hem coming loose after several months of wear, it is usually because the thread broke in one spot — you can re-sew just that section rather than the entire hem.

Common Mistakes and How to Avoid Them

The most common mistake is folding the hem unevenly, which makes it hang crooked. Measure carefully at multiple points before you fold, and use an iron to press each fold flat. A second mistake is sewing too far from the fold — if you sew more than 0.25 inches away, the hem can roll or come loose. Stay close to the inner fold.

Sewing over pins breaks needles and can damage the machine. Remove each pin just before the presser foot reaches it. Another frequent problem is using thread that does not match the fabric color — even a slightly lighter shade shows on dark fabric. Buy thread in the same color as the garment, or choose a shade one step darker.

If the hem puckers (gathers up in small wrinkles), the tension is too tight. Loosen the top tension slightly and test on a scrap before sewing the garment again. If the stitches are loose or the thread breaks, the tension is too loose — tighten it a little. Most machines have a dial marked 0 to 9; start at 5 and adjust from there.

Frequently Asked Questions

Can I hem stretchy fabrics like jersey or knit on a regular sewing machine?

Yes, but use a ballpoint needle (designed for knits) instead of a standard needle, and reduce the stitch length to 1.5 to 2.0 millimeters. Stretchy fabrics can curl at the edges, so consider using a narrow zigzag stitch instead of a straight stitch — it gives slightly more flexibility. You may also want to use a walking foot if your machine has one, as it feeds stretchy fabric more evenly.

What if the hem is too wide or too narrow after I sew it?

If it is too narrow (less than 0.5 inches), you can carefully remove the stitches with a seam ripper and re-fold the fabric with a wider hem. If it is too wide and bulky, you can trim the excess fabric inside the hem with scissors, leaving at least 0.25 inches of fabric above the stitches so the hem does not unravel. Always test the new width on a scrap first.

Do I have to press the hem with an iron before sewing?

Pressing is not absolutely required, but it makes sewing much easier because the fold stays in place without shifting. If you skip pressing, pin more frequently (every 1 to 2 inches instead of every 2 to 3 inches) and sew slowly. The final hem will look less crisp without pressing, but it will still be functional.

Can I use a different stitch, like a zigzag, for hemming?

A straight stitch is strongest and most common for hemming woven fabrics. A zigzag stitch is useful for stretchy or knit fabrics because it flexes with the fabric. For a decorative look, you can use a narrow zigzag or a specialty stitch, but straight stitch is the standard choice for durability and invisibility from the outside.

How do I fix a hem that came loose after washing?

If only a small section came loose, use a seam ripper to remove the old stitches in that area, re-fold the fabric, and sew over the same line with fresh thread. If the entire hem is loose, remove all the stitches and re-sew the whole hem. Check the thread tension and make sure you are using thread that matches the fabric — loose hems often mean the tension was too loose or the thread was too thin.