A hem is a folded edge you stitch down to shorten or finish fabric
A hem is the finished edge of a piece of fabric, usually created by folding the raw edge under and stitching it down. On a sewing machine, you fold the fabric twice (once to hide the raw edge, once more to create the hem itself), then sew a straight line near the fold. The two folds lock the raw edge inside, so it won't fray, and the stitching holds everything in place. This is the most common way to finish pants, skirts, dresses, and curtains.
The basic process takes about 15 to 30 minutes for a straightforward garment, depending on how long the hem is. You'll need a sewing machine, thread that matches your fabric, scissors, pins, and a measuring tape. Most hems are sewn with a straight stitch—the default setting on nearly every machine—so you don't need special skills or attachments to start.
Key Takeaways
- Measure and mark the finished hem length with pins or chalk before you fold, so the hem is even all the way around.
- Fold the fabric twice: first fold hides the raw edge, the second fold creates the hem itself, usually between one-quarter and one-half inch wide.
- Pin the folded hem in place every few inches to keep it from shifting while you sew.
- Sew with a straight stitch about one-eighth inch from the inner fold, using a thread color that matches your fabric.
- Press the finished hem with an iron to flatten it and make the stitches less visible.
Measure and mark the hem line before you fold anything
Start by deciding how long you want the finished garment to be. For pants, this is usually the length where the hem just touches the top of your shoe. For skirts and dresses, measure from the waistband down. For curtains, measure from the top to where you want them to end.
Put on the garment (or have someone wear it) and use a measuring tape to mark where the hem should fall. Mark this line all the way around with pins placed horizontally, or use tailor's chalk to draw a light line. The marks should be the same distance from the bottom edge all the way around—this is what makes the hem look even. If the garment is not being worn, lay it flat on a table and measure up from the bottom edge by the same amount at several points.
Once you have marked the line, try the garment on one more time to make sure the length looks right. It's much easier to adjust the marks now than to unpick stitches later.
Fold the fabric twice to hide the raw edge and create the hem
Lay the garment flat with the wrong side (the inside) facing up. Fold the bottom edge up to your marked line and press it flat with your fingers or an iron. This first fold hides the raw edge inside the garment.
Now fold the edge up again, about one-quarter to one-half inch, depending on how wide you want the finished hem to be. A one-quarter inch hem is narrow and works well for lightweight fabrics like cotton or linen. A one-half inch hem is sturdier and works better for heavier fabrics like denim or canvas. Press this second fold flat as well. The raw edge is now completely hidden inside the two folds.
For fabrics that fray easily (like knits or loosely woven materials), you can trim away some of the excess fabric before the second fold to reduce bulk. Trim to about one-quarter inch above the first fold, then fold again as usual.
Pin the hem to keep it from shifting while you sew
Place pins horizontally along the folded hem, spacing them about three to four inches apart. The pins should go through all the layers and hold the fold firmly in place. Pin from the inside of the garment so the pinheads don't get in the way of the presser foot.
As you sew, you'll remove each pin just before the presser foot reaches it. Never sew over a pin—it can break the needle or damage the machine. If you're hemming a long piece like curtains, you can pin as you go rather than pinning the entire hem at once.
Sew a straight line close to the inner fold
Thread your machine with thread that matches your fabric color. Set the machine to a straight stitch with a stitch length of about 2.0 to 2.5 millimeters (this is a standard setting on most machines). Raise the presser foot and slide the hemmed fabric under it, positioning the needle about one-eighth inch from the inner fold—the fold closest to the raw edge you just hid.
Lower the presser foot and sew slowly along the hem, removing pins as you approach them. Keep the fabric edge aligned so the stitching stays the same distance from the fold all the way around. Sew all the way to the end, then backstitch a few stitches to lock the thread and prevent unraveling.
If you're hemming a circular garment like the leg of pants, you'll sew all the way around until you meet your starting point. Overlap the stitches by about half an inch, then backstitch and cut the thread.
Press the finished hem to flatten it and hide the stitches
Once you've finished sewing, lay the garment flat and press the hem with an iron set to the temperature appropriate for your fabric. Press from the inside first, then flip and press from the outside. This flattens the stitches and makes them less visible, and it also helps set the fold so the hem holds its shape through washing and wearing.
If you see any puckering or uneven spots, you can gently stretch the fabric as you press to smooth them out. Let the garment cool completely before trying it on or folding it away.
Common mistakes and how to avoid them
The most common mistake is measuring unevenly, which makes the hem look crooked. Take your time with the measuring step and mark all the way around before you fold. If you discover the hem is uneven after sewing, you can unpick the stitches with a seam ripper, re-measure, and sew again—it's not permanent.
Another frequent problem is sewing too close to the outer fold, which can cause the stitches to show on the outside of the garment. Aim for one-eighth inch from the inner fold, and if you're unsure, sew a little farther away—a slightly wider stitch line is less noticeable than one that's too close to the edge.
Skipped stitches usually mean the needle is bent or the thread is not threaded correctly. Stop, rethread the machine, and try again on a scrap of fabric first. If stitches keep skipping, the needle may need replacing—needles wear out and should be changed every few projects.
Frequently Asked Questions
Can I sew a hem by hand instead of using a machine?
Yes. A hand-sewn hem uses a whip stitch or slip stitch and takes longer but gives a less visible finish on the outside. Use a needle and thread, and sew small stitches about one-quarter inch apart along the inner fold. Hand sewing is useful for delicate fabrics or when you want the hem to be nearly invisible.
What if my fabric is stretchy or a knit?
Knits and stretchy fabrics need a stitch that moves with the fabric. Use a narrow zigzag stitch instead of a straight stitch, or use a ballpoint needle designed for knits. The zigzag allows the hem to stretch without the stitches breaking. You may also want to use a narrower hem (one-quarter inch) to reduce bulk.
How do I fix a hem that came undone?
If only a small section has come loose, you can hand-sew it back down using a whip stitch and matching thread. If the entire hem has come out, unpick all the old stitches with a seam ripper, re-press the fold, and sew it again on the machine. Check that the fold is still even before you sew.
Should I use a special presser foot for hemming?
A standard presser foot works fine for most hems. Some machines come with a hemming foot or blind stitch foot, which can make certain types of hems easier, but they are not required. Stick with the standard foot until you're comfortable with the basic process.
What thread color should I use?
Use thread that matches your fabric as closely as possible. If you can't find an exact match, choose a shade slightly darker than the fabric rather than lighter—darker thread is less visible. For a decorative hem, you can use contrasting thread intentionally, but for a standard hem, matching thread disappears into the fabric.