The Basic Steps for Hemming Pants

To hem pants on a sewing machine, you measure how much fabric to remove, fold and pin the new hem, and sew a straight line around the leg opening. The whole process takes 20 to 30 minutes per pair once you have the right measurements. Most home sewers can do this successfully the first time if they work slowly and check their pins before sewing.

The key is getting the length right before you cut anything. Pants should break slightly on the top of your shoe when you stand flat-footed—that is, the hem should sit about half an inch above the heel. If you are hemming for someone else, have them wear the shoes they will actually wear with the pants.

Key Takeaways

  • Measure the desired hem length while wearing the shoes you will wear with the pants, standing flat on the ground.
  • Mark the new hem line with tailor's chalk or a fabric pen, then fold the fabric up and pin it in place before cutting.
  • Use a straight stitch on your machine set to medium length (2.0 to 2.5 mm), and sew about a quarter inch from the fold for a strong, invisible hem.
  • Press the hem with an iron after sewing to set the stitches and make the pants look finished.
  • Try on the pants before trimming the excess fabric inside the leg, in case you need to adjust the length.

Measuring and Marking the Hem Line

Start by putting on the pants with the shoes you plan to wear them with. Stand on a flat, hard surface—not carpet—and have someone else mark where the hem should fall. The mark should be at the back of the heel or just touching the top of the shoe. If you are working alone, use a mirror or take a photo to check the length.

Once you have the right length, measure up from that mark to the current hem. Write this number down. For example, if the pants are currently 2 inches too long, you need to remove 2 inches total. Measure this distance at the inside seam of both legs to make sure they are even—pant legs can stretch differently over time.

Use tailor's chalk or a fabric pen to mark a line around the inside of the leg at the new hem length. Mark on the inside of the pant leg, not the outside, so the line will not show. Make small marks every 2 to 3 inches around the leg, then connect them lightly with chalk. This line is your sewing guide.

Folding, Pinning, and Preparing to Sew

Turn the pant leg inside out. Fold the fabric up along your chalk line and press it flat with your fingers. The fold should be crisp and even all the way around. If the fold is wavy or uneven, unfold it and try again—a clean fold makes sewing much easier.

Pin the fold in place every 1 to 2 inches, pushing the pins through both layers of fabric. Place pins perpendicular to the fold (pointing toward the leg opening), not parallel to it. This way, you can sew right over the pins without stopping to remove them, or you can pull them out as you sew. Check that the fold is still even and the pins are holding it flat.

Before you cut anything, try on the pants one more time. Pull them on inside-out if you need to, and check that the fold sits where you want it. This is your final note to adjust. If the length is wrong, unfold, re-mark, and re-pin. Once you cut the excess fabric, you cannot add it back.

Sewing the Hem on Your Machine

Thread your machine with thread that matches the pants color. Set the stitch length to 2.0 to 2.5 mm—this is a medium length that holds well without puckering the fabric. Use a straight stitch, the default setting on most machines. If your machine has a needle-down option, turn it on so the needle stays in the fabric when you stop, making it easier to pivot at seams.

Position the pant leg under the presser foot so the needle will sew about a quarter inch from the fold. This distance—called the seam allowance—keeps the stitches hidden inside the fold. Lower the presser foot and sew slowly around the entire leg, keeping the fold edge even with the edge of the presser foot. Sew all the way around until you overlap your starting point by about half an inch, then backstitch to lock the thread.

Sew both legs the same way. Take your time, especially at the inseam where two layers of fabric meet—you may need to slow down or lift the presser foot slightly to get the needle through. If you hear the machine straining, stop and help guide the fabric through by hand rather than forcing it.

Trimming and Pressing the Finished Hem

Turn the pant leg right-side out and try it on to check the length one final time. If it looks right, turn it inside out again and trim the excess fabric to about a quarter inch above your stitching line. Use sharp scissors and cut slowly so you do not accidentally cut through the stitches. Leave enough fabric that the raw edge will not fray or come loose.

If your machine has a zigzag stitch, you can sew over the raw edge to prevent fraying, though this step is optional for most home sewing. Set the stitch width to 2.5 to 3.0 mm and sew along the cut edge, letting the needle swing over the edge of the fabric.

Press the hem with an iron on medium heat, pressing from the inside of the leg. Press the fold first, then open it up slightly and press the seam allowance flat. This sets the stitches and makes the hem look crisp and finished. Let the pants cool before trying them on.

Common Mistakes and How to Avoid Them

The most common mistake is measuring the hem length without wearing the shoes you will actually wear. Shoes with different heel heights change where the hem should fall, sometimes by an inch or more. Always measure in the actual shoes.

Another frequent problem is sewing too close to the fold, which makes the stitches visible on the outside of the pants. Keep the needle a quarter inch away from the fold so the stitches stay hidden inside. If you sew too far from the fold, the hem will be loose and may not hold the crease.

Uneven tension—where the thread is too tight or too loose—can cause puckering or skipped stitches. Check that your thread is wound correctly on the bobbin and that the top thread is seated properly in the tension discs. Test on scrap fabric before hemming the actual pants.

Rushing through the pinning step often leads to wavy or crooked hems. Spend the extra two minutes to pin every 1 to 2 inches and check that the fold is even before you sew. A straight hem takes longer to sew but looks much better.

Hemming Different Pant Styles

Straight-leg and slim-fit pants are the easiest to hem because the leg opening is consistent all the way around. Measure and sew as described above, and you will have good results.

Flared or wide-leg pants need extra care because the hem is wider and the fabric may have more weight. Pin more frequently—every inch instead of every 2 inches—and sew slowly. The extra fabric can bunch under the presser foot if you rush.

Tapered pants (where the leg gets narrower toward the ankle) are trickier because the fold may not be perfectly flat. Fold carefully and pin very close together. If the fold keeps popping up, you may need to use a ballpoint needle instead of a universal needle, as ballpoint needles slide between fibers rather than piercing them, reducing puckering on stretchy fabrics.

Pants with a cuff (a folded hem sewn on the outside) should not be hemmed by a home sewer unless you are comfortable unpicking the original cuff, hemming the leg, and re-sewing the cuff. This is a more advanced technique.

Frequently Asked Questions

How much fabric should I leave above my stitching line when I trim?

Leave about a quarter inch of fabric above the stitching line. This gives you enough material that the raw edge will not fray or come loose over time. If you trim too close to the stitches, the hem may unravel with washing and wearing.

Can I use a serger instead of a regular sewing machine to hem pants?

Yes, a serger creates a strong, finished edge that looks professional. However, sergers sew faster and are harder to control precisely, so they are better for sewers with some experience. A regular machine is more forgiving for your first hemming project.

What thread color should I use?

Match the thread to the pants color as closely as possible. If you cannot find an exact match, choose a shade slightly darker rather than lighter—dark thread is less visible in a fold. For dark pants, navy or black thread works for most colors.

Do I need to press the hem before sewing?

Pressing before sewing is optional but helpful. A light press with an iron sets the fold in place and makes it easier to keep the fold even while you sew. Use low heat so you do not scorch the fabric, and press from the inside of the leg.

What if I sewed the hem in the wrong place and need to fix it?

Use a seam ripper to carefully cut and remove the stitches, then unfold the fabric and re-mark the correct hem line. You can sew a new hem in the right place. The old stitch holes may be slightly visible, but they will fade with washing.