A hem is a folded edge of fabric sewn down to finish the bottom of a garment

A hem is straightforward fabric folded up and stitched in place to create a finished edge. On a sewing machine, you fold the fabric twice (to hide the raw edge inside), then sew a straight line near the fold. The whole process takes 10 to 20 minutes for a straightforward garment like pants or a skirt, and the stitch is nearly invisible from the outside if you measure and press carefully before you sew.

The most common mistake is skipping the pressing step. Fabric that is not pressed flat will pucker under the presser foot, and your hem will look wavy. The second mistake is sewing too close to the fold—if your stitch line is right at the edge, it will show from the outside. You want the needle about one-quarter inch away from the fold, so the stitch sits on the flat part of the hem.

Key Takeaways

  • Measure the hem height from the bottom of the garment up (usually one to two inches for pants, one-half to one inch for lighter fabrics), mark it with pins or chalk, and fold the fabric up to that line.
  • Fold the raw edge up again by one-half inch, press both folds flat with an iron, and pin the hem in place every two to three inches.
  • Thread your machine, set it to a straight stitch at medium speed, and sew one-quarter inch away from the inner fold so the stitch does not show from the outside.
  • Backstitch at the start and end of each seam to lock the thread and prevent the hem from unraveling.
  • Try on the garment before you cut any threads—if the length is wrong, you can pull out the stitches and adjust.

Measure and mark the hem length

Start by putting on the garment and standing in front of a mirror. Have someone else measure from the floor to where you want the hem to end, or measure yourself with a ruler held straight up from the floor. Write down that measurement—for example, "two inches from the floor" or "one inch up from the current edge."

Take off the garment and lay it flat on your work surface. Measure up from the bottom edge the distance you want the finished hem to be (usually one to two inches for pants, one-half to one inch for dresses or skirts). Use a ruler and a fabric pencil, chalk, or pins to mark a line all the way around. If you use pins, place them every three to four inches; if you use chalk or pencil, draw a light line you can see but will not show after sewing.

Fold and press the hem twice

Fold the fabric up along the line you marked. The raw edge (the unfinished bottom) should now be facing up. Press this fold flat with an iron set to the heat level for your fabric—check the garment tag if you are unsure. A hot iron makes a crisp fold that is easier to sew straight.

Now fold the raw edge up again by one-half inch, so it is hidden inside the fold. Press this second fold flat as well. You now have a double-folded hem with no raw edges showing. This is what protects the fabric from fraying and makes the hem look finished on both sides.

Pin the hem in place

Once both folds are pressed, pin the hem to the garment every two to three inches. Place pins perpendicular to the fold (pointing toward the body of the garment, not along the edge). Pins placed this way will not catch the presser foot as you sew, and they are straightforward to pull out as you work.

Check that the hem is even all the way around by measuring from the fold to the body of the garment in several places. If one section is higher or lower than the rest, unpin it, re-press, and pin again. Uneven hems are the second most common mistake after skipping the press step.

Thread the machine and set up for sewing

Wind a bobbin with thread that matches your fabric, or use a pre-wound bobbin if you have one. Insert the bobbin into the bobbin case, thread the top of the machine, and pull both the top thread and bobbin thread under the presser foot. Lower the presser foot to engage the tension discs.

Set your machine to a straight stitch (the default on most machines) and adjust the stitch length to 2.5 millimeters—this is small enough to hold the hem securely but large enough to see and remove if you need to adjust. Set the speed to medium so you have time to guide the fabric smoothly. Do a test stitch on a scrap of the same fabric folded the same way to check that the tension is even and the stitch looks the same on both sides.

Sew the hem with a straight stitch

Position the garment under the presser foot so the needle will land about one-quarter inch away from the inner fold (the fold closest to the body of the garment). This distance is crucial—if you sew right at the fold, the stitch will show from the outside. If you sew too far away, the hem will not hold.

Backstitch three or four stitches to lock the thread at the start. Then sew forward slowly, keeping the fold line straight under the presser foot. Remove pins as you approach them—do not sew over pins, as this can break the needle. When you reach the end of the hem, backstitch three or four stitches again to lock the thread. Raise the presser foot, pull the garment out, and trim the threads close to the fabric.

Try on the garment and check the length

Put on the garment and look at the hem in a mirror. The length should be even all the way around, and the stitch should not be visible from the outside. If the length is wrong, you can pull out the stitches with a seam ripper (a small tool with a curved hook) and re-sew. If the stitch is visible, you may have sewn too close to the fold—this is usually only noticeable if you look closely, and it becomes less obvious after the garment is washed a few times.

If the hem looks good, press it one more time with an iron to set the stitch and remove any wrinkles from handling. The hem is now complete and will hold through many washes if you used thread that matches your fabric and backstitched at both ends.

Frequently Asked Questions

What if my fabric is stretchy or slippery?

Stretchy fabrics like knits and lycra need a stretch stitch (often labeled as a lightning bolt or wavy line on your machine) instead of a straight stitch, because a straight stitch will snap when the fabric moves. Slippery fabrics like satin or silk are easier to control if you use a walking foot, which feeds the fabric evenly and prevents shifting. If you do not have a walking foot, sew more slowly and use your hands to guide the fabric gently.

Can I sew a hem by hand instead of on a machine?

Yes. A hand-sewn hem using a slip stitch or whip stitch is actually invisible from the outside and is often preferred for delicate fabrics or heirloom garments. It takes longer (30 to 45 minutes) but gives you more control. Use a needle that fits your thread, knot the thread at one end, and sew small stitches that catch only a few threads of the fold and the garment body.

What stitch length should I use for a hem?

A stitch length of 2.5 millimeters is standard for most hems and fabrics. Lighter fabrics like cotton voile or linen can use 2.0 millimeters for a tighter hold. Heavier fabrics like denim or canvas can use 3.0 millimeters. If your machine uses numbers instead of millimeters, 2.5 is usually marked as a medium setting.

Why does my hem pucker or look wavy?

Puckering usually means the fabric was not pressed flat before sewing, or you are pulling the fabric as you sew. Always press with an iron before you sew, and let the presser foot and feed dogs move the fabric—do not pull or push. If puckering happens only in one spot, that section may have been folded unevenly. Unrip it, re-press, and sew again.

How do I remove a hem if I made a mistake?

Use a seam ripper to cut every third or fourth stitch along the hem, then pull the thread out. Work slowly to avoid tearing the fabric. Once the stitches are out, press the fabric flat again to remove the crease, re-measure and re-fold if needed, and sew a new hem. The old stitch holes will disappear after one wash.