A sewing machine hem is faster and stronger than hand-sewing

A machine hem is a fold of fabric sewn down with your sewing machine to shorten pants, skirts, curtains, or other items. The machine stitches through two layers of folded fabric, locking them together so the hem won't unravel. Most hems take 10 to 20 minutes once you measure and pin, and the stitch holds through dozens of washes.

The basic process is: measure how much fabric to remove, fold the edge up twice to hide the raw edge, pin it in place, and sew a straight line near the fold. The second fold is what makes a machine hem look finished—it keeps fraying threads hidden inside.

Key Takeaways

  • Measure from the hem line (where you want the fabric to end) up to the current edge, then add half an inch for the fold allowance before you cut.
  • Fold the raw edge up a quarter inch, then fold it up again by the full hem width you want (usually half an inch to one inch), and pin every two inches.
  • Use a straight stitch, thread color that matches the fabric, and sew slowly along the inner fold line so the stitches don't show on the outside.
  • Press the hem flat with an iron after sewing to set the crease and make the hem lie smooth.

Measure and mark before you cut anything

Put on the garment or hold the fabric at the length you want it to be. Have someone else measure from the floor (or your chosen endpoint) straight up to where you want the hem to sit. Write this measurement down—this is your finished length.

Lay the garment flat on a table. Measure from the current raw edge up toward the fabric, and mark with a pen or chalk where you want to cut. Add half an inch to your finished length measurement to account for the fold allowance. For example, if you want a one-inch hem and your finished length is 30 inches, mark at 31.5 inches and cut there. This gives you fabric to fold without running short.

Cut straight across with sharp fabric scissors. A crooked cut makes the hem uneven, so take your time here.

Fold the edge twice to hide the raw threads

Fold the raw edge up toward the inside of the garment by a quarter inch. Press this fold flat with your fingers or an iron. This first fold hides the raw edge so it won't fray.

Now fold the fabric up again by the width of your finished hem. If you want a half-inch hem, fold it up half an inch. If you want a one-inch hem, fold it up one inch. Press this second fold flat as well. The raw edge is now tucked inside the two layers, completely hidden.

Pin the folded hem every two inches along the length. Push pins straight through both layers so they hold the fold in place while you sew. The pins should go in perpendicular to the edge—not parallel—so you can sew over them without breaking your needle.

Thread your machine and choose the right stitch

Wind a bobbin with thread that matches your fabric color as closely as you can. Thread the top of the machine the same color. If you cannot find an exact match, choose a shade slightly darker than the fabric—it will be less visible than a lighter shade.

Set your machine to a straight stitch with a stitch length of 2.0 to 2.5 millimeters. This is the standard setting on most machines and creates a line of small, even stitches that hold the hem securely without puckering the fabric.

Test the tension on a scrap of fabric folded the same way as your hem. Sew a short line and look at both sides. The stitches should look the same on top and bottom—not loose loops on either side. If the top thread is loose, increase tension slightly. If the bottom thread is loose, decrease tension. Most machines have a dial numbered 0 to 9; start at 5 and adjust by half a number at a time.

Sew slowly along the inner fold line

Position the fabric under the presser foot so the needle will sew along the inner fold—the line where the second fold meets the single layer of fabric. This is where the stitch should sit so it does not show on the outside of the garment. Lower the presser foot to hold the fabric in place.

Sew forward slowly, removing pins as you approach them. Do not sew over pins; they can break your needle or bend it out of alignment. Keep the fold line straight under the needle by guiding the fabric gently with your hands, but do not pull or push hard—let the machine feed the fabric at its own pace.

When you reach the end, backstitch by pressing the reverse button for a half inch, then sew forward again to lock the thread. Raise the presser foot and pull the fabric toward you to cut the thread tails.

Press the hem flat to finish

Lay the garment on an ironing board with the hem facing up. Set your iron to the heat setting for your fabric type—check the care tag if you are unsure. Press the hem flat with firm, even pressure for 10 to 15 seconds. This sets the crease and makes the stitches sit smoothly.

Flip the garment over and press the outside as well to blend the hem into the rest of the fabric. Let it cool for a minute before wearing or washing.

Common mistakes and how to avoid them

The most common error is folding the hem only once instead of twice. A single fold leaves the raw edge exposed, and it will fray after a few washes. Always fold twice—once to hide the edge, once to create the finished hem width.

Another mistake is sewing too close to the outer edge of the fold. If your stitches are too close to the outside, they will show when the garment is worn. Sew along the inner fold line instead, where the two layers meet. The stitches will be hidden inside the fold.

Uneven hems usually come from not pressing the fold flat before sewing. If the fold is wavy or loose, the hem will be crooked. Take time to press with an iron before you pin and sew.

When to call in a professional

If your fabric is stretchy (like knit or jersey), a machine hem can pucker because the needle pulls the fabric as it sews. A professional tailor has techniques and sometimes a special presser foot to handle stretchy fabrics. The same applies to very heavy fabrics like denim or canvas—they require a heavy-duty needle and careful tension adjustment.

If you have never used a sewing machine before, practice on a scrap of similar fabric first. Sew a practice hem, press it, and look at how it turned out. This takes 10 minutes and will show you whether your tension and stitch length are right before you commit to your actual garment.

Frequently Asked Questions

What if my hem comes out wavy or puckered?

Wavy hems usually mean the fold was not pressed flat before sewing, or the fabric was pulled while sewing. Redo the hem: remove the stitches with a seam ripper, press the fabric flat again, re-fold and pin, and sew more slowly without pulling. Puckering on stretchy fabric is normal with a regular presser foot; a tailor can use a ballpoint needle or walking foot to prevent it.

Can I use a different stitch instead of straight stitch?

A straight stitch is the standard because it is strong and invisible. A zigzag stitch is visible and not necessary on a folded hem because the raw edge is already hidden. Save zigzag for raw edges that are not folded. Stick with straight stitch for hems.

How do I remove a hem if I sew it wrong?

Use a seam ripper—a small tool with a curved blade that cuts thread without damaging fabric. Slide the blade under a stitch every half inch and cut, then pull the thread out. It takes patience but works on any fabric. Once the stitches are out, press the fabric flat and start over.

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

No. A standard presser foot works fine for most hems. Some machines have a hemming foot that guides the fold, but it is not necessary. A regular foot and a steady hand are enough.

What thread weight should I use?

Use all-purpose thread for most fabrics—it is strong enough and comes in many colors. For very heavy fabrics like canvas or upholstery, use heavy-duty thread. For delicate fabrics like silk or chiffon, use fine thread. The thread should match the fabric color, not the garment color.