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To hem pants with a sewing machine: mark the new length with the wearer in their shoes, add a hem allowance, cut, press the hem up, then sew it. Use a blind hem stitch and blind hem foot for dress pants, a straight topstitch for jeans and casual pants, or a twin needle for knits. When hemming trousers with a sewing machine, the free arm makes the whole job easier, because the trouser leg slides around it as you go.
The steps below work on almost any home machine. The only setting that really differs between machines is the blind hem stitch, so keep your manual handy for that part.
Hemming Trousers with a Sewing Machine: What You Need
- Your sewing machine, with a free arm (remove the accessory tray or extension table)
- A blind hem foot for dress pants (most beginner machines include one)
- The right needle: Universal 80/12 or 90/14 for most trouser fabrics, Jeans 90/14 to 110/18 for denim, Stretch or Jersey for knits (see our needle size chart)
- Thread matched to the trousers (go a shade darker if you can't match exactly)
- Tailor's chalk or a washable marker, a seam gauge or ruler, pins or clips
- An iron and pressing cloth, and sharp fabric scissors
Step 1: Mark the New Length
- Have the wearer put on the trousers with the shoes they'll wear with them. Heel height changes the length a lot.
- Fold the hem under until it falls where you want it. For dress pants, that's usually a slight break over the shoe, or none for a modern cut. Casual pants can sit a little shorter.
- Pin the fold at the front and back of each leg, and check both legs in a mirror. Legs aren't always the same length.
- Take the trousers off and measure from the fold to the raw edge of the existing hem. Use the same measurement on both legs unless the wearer needs different lengths.
Step 2: Unpick, Measure and Cut
- Unpick the original hem with a seam ripper, and press the old fold flat. Note how deep it was; it's a good guide for the new allowance.
- Chalk the new hemline (the fold line) all the way around each leg, measuring up from the old hem.
- Add your hem allowance below the hemline and chalk a cutting line. Common practice: - Dress pants (blind hem): about 1 1/2 to 2 inches - Casual pants (double fold): about 1 inch, folded 1/2 inch twice - Jeans (double fold): about two folds of 1/2 inch, or match the original - Knit pants: about 1 to 1 1/4 inches, single fold
- Cut along the cutting line. Measure twice; you can't add fabric back.
Step 3: Finish the Raw Edge (Dress Pants)
For a single-fold blind hem, finish the raw edge so it won't fray inside the hem. Use a zigzag or overcast stitch along the edge, or a serger if you have one. Skip this step for double-fold hems, where the raw edge is enclosed.
Step 4: Press the Hem
- Fold the hem up along the hemline and press it from the inside, using a pressing cloth on wool or dark fabrics so they don't shine.
- For a double-fold hem, fold the raw edge under by half first, press, then fold again and press.
- Pin or clip the hem every few inches, with the pins perpendicular to the edge.
A well-pressed hem is half the job. It stops the fabric from twisting as you sew.
Step 5A: Sew a Blind Hem (Dress Pants)
The blind hem stitch is how you get a nearly invisible machine hem. It sews a few straight stitches into the hem allowance, then one sideways "bite" that just catches the trouser leg.
- Select the blind hem stitch and attach the blind hem foot. Check your manual for the recommended stitch width and length; they vary by machine.
- Fold the hem for blind hemming. With the trousers inside out, fold the hem allowance up as pressed, then fold the trouser leg back over it so about 1/4 inch of the finished hem edge sticks out to the right.
- Slide the leg onto the free arm and place the fold against the guide on the blind hem foot.
- Turn the handwheel by hand for the first few stitches and check that the sideways stitch just catches one or two threads of the fold. If it bites too much, it will show on the outside. If it misses, the hem won't hold. Adjust the stitch width or the foot's guide to fine-tune it.
- Sew slowly around the leg, keeping the fold against the guide. Overlap the starting stitches by about 1/2 inch, then tie off or backstitch.
- Unfold and press the hem from the inside.
Practice on a scrap of the same fabric first. It takes a few tries to judge the bite, and after that it's fast.
Step 5B: Sew a Topstitched Hem (Jeans and Casual Pants)
- Install a Jeans needle, 90/14 to 100/16 for most denim. SCHMETZ recommends its Jeans needle from 70/10 to 110/18 for denim, so size up for heavy jeans. Topstitching thread looks closest to a factory hem; use a Topstitch needle or a larger size with it.
- Set a straight stitch about 3 to 3.5 mm long, which looks better and sews thick fabric more easily than a short stitch.
- With the trousers right side out, slide the leg onto the free arm and start sewing at the inseam, close to the inner fold edge.
- Slow down over the side seams. These are the thickest spots. Turn the handwheel by hand to walk the needle over them. A folded scrap of denim behind the foot helps keep the foot level as you climb the seam.
- Overlap the starting stitches, then backstitch or pull the threads to the inside and tie them off.
- Press.
If your machine struggles with denim seams, our heavy-duty sewing machine guide covers machines with stronger motors and higher presser foot lifts.
Step 5C: Hem Knit Pants
Knit hems have to stretch, or the stitches will snap when you pull the pants on.
- Use a Stretch or Jersey (ball point) needle, or a stretch twin needle. SCHMETZ makes its Stretch Twin in 2.5/75 and 4.0/75.
- Fold and press a single hem, and pin or clip it.
- Sew from the right side with a twin needle, which gives two parallel rows on top and a zigzag underneath, just like ready-to-wear hems. Or use a narrow zigzag or your machine's stretch stitch.
- Don't stretch the fabric as you sew. Let the feed dogs move it.
Hemming Settings at a Glance
| Trouser type | Hem style | Stitch | Needle | Foot |
|---|---|---|---|---|
| Dress pants, wool, suiting | Single fold, blind hem | Blind hem | Universal 80/12 to 90/14 | Blind hem foot |
| Chinos and casual cotton | Double fold | Straight, 3 to 3.5 mm | Universal 80/12 to 90/14 | Standard foot |
| Jeans | Double fold, topstitched | Straight, 3 to 3.5 mm | Jeans 90/14 to 110/18 | Standard or jeans foot |
| Knit pants, joggers, leggings | Single fold | Twin needle or narrow zigzag | Stretch, Jersey or stretch twin | Standard foot |
Needle sizes follow SCHMETZ's fabric recommendations (Universal 70/10 to 100/16 for wool and gabardine; Jeans for denim). Machine stitch settings are typical starting points, so test on scrap.
Common Mistakes When Hemming Pants
- Measuring without shoes. Always mark the length with the right shoes on.
- Cutting before checking both legs. Pin and check both before you trim anything.
- Skipping the pressing. An unpressed hem twists and comes out uneven.
- Taking too big a bite on a blind hem. The stitches will show as dots on the outside. Adjust until the bite catches just a thread or two.
- Forcing jeans seams. Slow down, use a Jeans needle and walk the needle by hand over the side seams.
- Using a straight stitch on knits. It won't stretch and the threads will pop.
- Sewing a closed leg on the flatbed. Use the free arm, or you risk sewing the leg shut.
FAQ
How much hem allowance should I leave on pants?
Common practice is about 1 1/2 to 2 inches for dress pants with a blind hem, and about 1 inch for a casual double-fold hem (two 1/2-inch folds). Jeans are often hemmed with two folds of about 1/2 inch. If the trousers already have a deep hem, unpick it and reuse the same allowance.
Can you hem dress pants with a sewing machine without the stitches showing?
Yes. Use the blind hem stitch with a blind hem foot. The machine sews several straight stitches in the hem allowance, then one sideways stitch that just catches the trouser leg, so only a tiny dot shows on the outside. Matching thread and a test on scrap make it nearly invisible.
What stitch do you use to hem pants on a sewing machine?
Use a blind hem stitch for dress pants and wool trousers, a straight stitch (about 3 to 3.5 mm long) for a topstitched hem on jeans and casual pants, and a twin needle or narrow zigzag for knit pants so the hem can stretch.
What needle should I use to hem jeans?
Use a Jeans needle. SCHMETZ recommends its Jeans needle in 70/10 to 110/18 for denim; a 90/14 or 100/16 suits most jeans hems, and a larger size helps over the thick side seams. Slow down and walk the needle by hand over the bulkiest spots.
Should I hem pants by hand or by machine?
A machine blind hem is faster and very durable, and it's nearly invisible on most fabrics. A hand blind stitch or slip stitch is even less visible and is the traditional finish on fine wool suiting. On jeans and casual pants, a machine topstitched hem is standard. Our hand sewing stitches guide shows the slip stitch.
Need a Machine or a Blind Hem Foot?
Most beginner machines include a blind hem foot, and our presser feet guide shows how it works alongside the other feet. If you're shopping, a free arm and a blind hem foot in the box are the two features that matter most for hemming. Brother's budget XM2701, which leads our cheap sewing machines list, ships with a blind stitch foot and a narrow hemmer. New to the machine? Start with how to use a sewing machine.