The basic steps for a hand-sewn or machine-sewn hem

A hem is the folded edge of fabric that you stitch down to finish the bottom of pants, skirts, sleeves, or curtains. The process is the same whether you sew by hand or machine: measure how much fabric you want to fold up, fold it, press it flat, and stitch it down. Hand sewing takes longer but gives you more control and leaves almost no visible stitching on the outside. Machine sewing is faster and stronger, but the stitches show on the inside of the garment.

The most common hem depth is between one-half inch and one inch for lightweight fabrics like cotton shirts, and one to two inches for heavier fabrics like denim or wool. Pants hems are usually one to one-and-a-half inches. Curtains can be deeper — two to three inches — because the weight helps them hang straight.

Key Takeaways

  • Measure and mark your hem line with chalk or a fabric pen, then fold the fabric up and press it with an iron to crease the fold.
  • For a hand-sewn hem, use a needle and thread to make small stitches that catch only a few threads of the outer fabric so they stay hidden.
  • For a machine-sewn hem, fold the fabric twice (once to the marked line, then fold again to hide the raw edge) and stitch close to the inner fold.
  • Try on the garment before you finish sewing to make sure the hem length looks right and hangs evenly.

Measure and mark the hem line

Put on the garment or have someone else wear it while you measure. Use a ruler or measuring tape to find where you want the hem to end — usually at the ankle for pants, just below the knee for skirts, or at your wrist for sleeves. Mark this line all the way around with tailor's chalk, a fabric pen, or a pencil. Make small marks every few inches rather than one long line, so you can see them clearly when you fold.

If you are hemming something that will not be worn — like a tablecloth or curtains — measure from the edge and mark a straight line. Use a ruler and a hard surface like a cutting mat to keep the line even. For a curtain, measure from the top down to find the length you want, then mark the hem line on the back of the fabric.

Fold and press the hem

Fold the fabric up along your marked line and press it flat with an iron set to the heat level for your fabric type. Cotton and linen take high heat; synthetics and blends need medium heat. Press for a few seconds until the fold is sharp and creased. This crease is your guide for sewing and helps the hem stay in place while you work.

For a hand-sewn hem, you can stop here and move to stitching. For a machine-sewn hem, fold the raw edge (the unfinished edge) up toward the crease by about one-quarter inch, then press again. This second fold hides the raw edge inside the hem so it does not fray. The hem is now ready to stitch.

Hand-sewing a hem with a slip stitch

Thread a needle with thread that matches your fabric. Knot the end. Slide the needle into the fold of the hem so the knot stays hidden inside, then bring the needle out through the fold about one-quarter inch along. Catch just two or three threads of the outer fabric (the part of the garment above the hem), then slide the needle back into the fold for another one-quarter inch. Bring it back out and repeat.

The stitches should be small and tight — about one-eighth inch long — so they do not show on the outside of the garment. If you pull too hard, the fabric will pucker. If you pull too loose, the hem will come undone. Aim for even tension: the thread should be snug but not straining. When you reach the end, make two small stitches in the same spot, then slide the needle through the fold and cut the thread.

This stitch is called a slip stitch or ladder stitch because the thread runs inside the fold and only catches the outer fabric at intervals, leaving the inside of the hem almost invisible.

Machine-sewing a hem with a straight stitch

Set your machine to a straight stitch with a stitch length of about 2.5 millimeters (a medium length). Use thread that matches your fabric. Position the folded hem under the presser foot so the needle will stitch close to the inner fold — this is the fold you made when you tucked the raw edge up. The stitches will be visible on the inside of the garment but not on the outside.

Sew slowly and keep the fold straight under the presser foot. Backstitch at the beginning and end to lock the stitches. If the hem is long, stop every few inches, lift the presser foot, and adjust the fabric so it stays straight. Crooked stitches are harder to fix than slow stitches.

For a stronger hem on heavy fabric like denim, you can sew two rows of stitches — one close to the inner fold and one closer to the raw edge. This is called a double-stitched hem and is common on jeans.

Check the length before you finish

Try on the garment or hold it up to check that the hem hangs evenly and looks the right length. Look at it from the side and from the front. If one side is longer than the other, you may have folded unevenly. If the whole hem is too long or too short, you will need to open it up, re-mark the line, and sew again.

For pants, stand in the shoes you will wear with them. For skirts, check the length sitting down as well as standing, since sitting can change how the hem looks. For sleeves, let your arms hang naturally at your sides. Once you are happy with the length, you can finish sewing if you have not already.

Finishing the hem edges

If you hand-sewed the hem, the raw edge inside may fray over time, especially if you wash the garment often. You can finish it by hand with a whip stitch (similar to the slip stitch but catching the raw edge itself), or you can trim it close and leave it as is if the fabric does not fray badly. Cotton and linen fray more than synthetics.

If you machine-sewed the hem and did not fold the raw edge up before stitching, you can finish it now by trimming it close with scissors and then sewing a zigzag stitch along the edge to prevent fraying. Some machines have a serger stitch or overlock stitch that does this in one pass. Alternatively, you can use pinking shears (scissors with a zigzag blade) to cut the edge, which also slows fraying.

Frequently Asked Questions

What thread should I use for hemming?

Use thread that matches your fabric color as closely as possible. For hand sewing, all-purpose polyester or cotton thread works well. For machine sewing, use the same weight thread in the bobbin and the needle. If you cannot find an exact match, choose a shade slightly darker than the fabric, as it will be less visible than a lighter shade.

Can I use a sewing machine to hem knit fabrics?

Yes, but use a ballpoint needle (designed for knits) and a stretch stitch or narrow zigzag stitch instead of a straight stitch. Straight stitches can break when knit fabric stretches. You can also hand-sew a knit hem with a slip stitch, which is often easier and gives a neater result.

What if my hem keeps coming undone?

The stitches may be too loose, or you may not have caught enough fabric in each stitch. For hand sewing, make sure you are catching at least two threads of the outer fabric and keeping tension even. For machine sewing, check that your thread is threaded correctly and that the needle is not bent or dull. A bent needle will skip stitches. Replace it and try again.

How do I fix a hem that is uneven?

Open the stitches with a seam ripper (a small tool with a curved blade), then carefully pull out the thread. Press the fabric flat to remove the old crease. Re-measure and mark a new hem line, then fold, press, and sew again. Take your time measuring the second time to avoid repeating the mistake.

Can I hem pants without trying them on?

Not accurately. Hem length depends on your height, the shoe heel you will wear, and how the pants fit at the waist — all of which affect where the hem should fall. Try them on in the shoes you plan to wear, or have the person who will wear them try them on. This takes a few extra minutes but prevents having to redo the hem.