The basic steps to hem pants on a sewing machine
Hemming pants on a sewing machine takes about 30 minutes once you know the steps. You measure how much fabric to remove, fold and pin the new hem, then sew a straight line around the pant leg. The machine does the work — you guide the fabric and keep the stitches even.
Start by putting on the pants and having someone mark where the hem should hit your shoe with a piece of chalk or a safety pin. Take the pants off and measure from that mark down to the original hem. Subtract half an inch (this becomes the fold line), then add another inch for the seam allowance. That total is how much you cut off the bottom.
Fold the cut edge up by half an inch, press it flat with an iron, then fold it up again by the full seam allowance amount and press again. Pin the fold in place every 2 to 3 inches around the leg. Thread your machine with thread that matches the pants, set it to a straight stitch, and sew slowly around the entire hem, staying about a quarter inch from the fold.
Key Takeaways
- Measure the desired hem length while wearing the pants, then mark it with chalk or a pin before you cut anything.
- Cut off the excess fabric, then fold the raw edge up twice and press with an iron to create a clean, finished hem.
- Pin the folded hem in place every few inches to keep it from shifting while you sew.
- Use a straight stitch on medium speed and sew a quarter inch from the fold for a durable, invisible hem.
- Press the finished hem with an iron to flatten the stitches and give the pants a professional appearance.
Measuring and marking the correct hem length
The hem should hit just at the top of your shoe when you stand flat. If you mark it too high, the pants will look short; too low and they will drag and fray. Have someone else mark it if possible — it is hard to see the back of your own leg.
Put on the pants with the shoes you plan to wear them with. Stand on a flat surface and have the other person use tailor's chalk, a fabric pencil, or a safety pin to mark the spot all the way around the leg. If you are hemming alone, put on the pants and use a mirror to mark the front and sides, then ask someone to mark the back.
Once marked, take the pants off and measure from the mark down to the existing hem with a ruler or measuring tape. Write this number down — you will need it to know how much fabric to remove. For example, if the mark is 2 inches above the current hem, you will cut off 2 inches plus a half inch for the fold.
Cutting and preparing the fabric
Cut straight across the pant leg using sharp fabric scissors or a rotary cutter. A crooked cut will make the hem uneven, so take your time and cut in one smooth motion if you can. If you are nervous, mark a line with tailor's chalk first and cut along it.
After cutting, fold the raw edge up by half an inch and press it flat with a hot iron. This fold seals the raw edge and prevents fraying. Then fold the entire hem up by the full seam allowance (usually 1 to 1.5 inches) and press again. The fold should be crisp and even all the way around the leg.
If the pant leg is curved or tapered, the hem may bunch slightly at the fold. Gently stretch the fabric as you press to smooth out small wrinkles. For very tight pant legs, you may need to trim a tiny bit more fabric or use a narrower seam allowance to avoid bulk.
Pinning the hem in place
Pins hold the folded hem steady while you sew and prevent it from shifting under the presser foot. Place a pin every 2 to 3 inches around the entire leg, pushing the pin through both layers of the fold and into the pant leg below.
Make sure the fold is even and the pins are perpendicular to the fold line — not at an angle. If the hem dips or rises as you pin, stop and re-press that section with the iron. Uneven pinning leads to an uneven hem, which is visible when you wear the pants.
For pant legs with a seam (the line running up the inside and outside of the leg), place a pin right at the seam on both sides. This helps you keep the hem level as you sew around the curve of the leg.
Setting up the sewing machine
Thread the machine with thread that matches the pants as closely as possible. If you cannot find an exact match, choose a shade slightly darker rather than lighter — dark thread is less visible on most fabrics. Use all-purpose polyester thread, which works on most pants fabrics.
Set the machine to a straight stitch with a stitch length of 2.0 to 2.5 millimeters. This length is standard for hemming and creates a durable seam that will not break easily. If your machine has a needle position dial, center it so the needle runs down the middle of the presser foot.
Test the tension on a scrap of fabric first. The top and bottom threads should lock together in the middle of the fabric layers — if the top thread is loose and loopy, tighten the tension dial slightly. If the bottom thread shows on top, loosen the tension. Most machines come set correctly, but testing takes 30 seconds and prevents mistakes on your pants.
Sewing the hem
Slide the pant leg under the presser foot with the fold facing you. Position the needle about a quarter inch from the fold — this distance keeps the stitches hidden inside the fold when you wear the pants. Lower the presser foot and begin sewing slowly, guiding the fabric with your hands but letting the machine feed it.
Sew all the way around the leg in one continuous line. When you reach a seam, slow down and take one stitch at a time if the fabric feels thick. At the end, overlap your stitches by about half an inch to lock the seam, then backstitch a few times and cut the thread.
If you notice the hem bunching or puckering as you sew, stop when ready, raise the presser foot, and pull the fabric out gently. Re-pin that section and try again. Puckering usually means the fabric is being fed unevenly or the tension is too tight.
Finishing and pressing the hem
Once the stitching is complete, try on the pants and check that the hem is even and sits where you want it. If one side is higher than the other, you can carefully remove a few stitches with a seam ripper and adjust the fold, then re-sew that section.
Press the finished hem with a hot iron to flatten the stitches and give the pants a polished look. Place the iron on the seam line and press from the inside of the pant leg, then flip and press from the outside. This heat-sets the fold and makes the hem less visible.
Trim any loose threads with scissors. If the raw edge of the fold is still visible from the outside, you can explore a thin line of fray check (a clear liquid that seals fabric edges) along the cut edge. Let it dry completely before wearing the pants.
Frequently Asked Questions
What if I sew the hem crooked?
Use a seam ripper to carefully cut and remove the stitches, then re-press the fold and sew again. Seam rippers are inexpensive and make removing stitches quick. If only a small section is crooked, you can remove just that part and re-sew it without taking out the whole hem.
Can I hem pants with a pattern or texture?
Yes, but match the pattern at the seams if possible. For example, if the pants have vertical stripes, align the stripe at the inside and outside seams so the pattern looks continuous around the leg. This takes a bit more care when measuring and cutting but uses the same sewing steps.
How do I hem pants with a cuff or rolled edge?
Cuffed pants require a different approach — you fold the hem up higher (usually 1.5 to 2 inches) and sew it so the cuff rolls naturally. Measure the original cuff width and keep it the same. If you are unsure, take the pants to a tailor for the first cuff hem, then you can copy the technique on future pairs.
What thread weight should I use?
All-purpose polyester thread in a matching color works for most pants. Avoid heavy upholstery thread, which is too thick and will show. If the pants are very lightweight (like linen or silk), use a finer thread to avoid creating a visible ridge along the hem.
How long does a machine-sewn hem last?
A properly sewn hem lasts as long as the pants themselves — often several years of regular wear. The key is using the right stitch length (not too short, which weakens the fabric) and matching thread. If a hem does come loose, you can re-sew it in minutes.