Step-by-Step: How To Hem Jeans With Sewing Machine

You want to know how to make your pants shorter using a sewing machine? This guide shows you how to hem jeans with sewing machine help. It walks you through the simple steps to shorten jeans so they fit just right. You will learn about the tools you need, like a strong denim needle and heavy duty thread, and two ways to do it: a basic hem and how to keep original hem jeans. This way, your favorite pants will fit your leg length perfectly.

Why Fix Your Jeans?

Sometimes, new jeans are too long. Or maybe your favorite old ones have worn-out bottoms. Making them shorter fixes these problems. It makes your jeans fit better and look nicer. Sewing denim can seem hard, but with the right steps, it’s easy. You can do it yourself at home.

Get Your Tools Ready

Before you start, gather everything you need. Having the right things makes the job go smoothly.

What You Need

Your jeans you want to shorten
A sewing machine
A specific needle for sewing denim (a denim needle is best)
Strong thread (heavy duty thread works well)
Fabric scissors (sharp ones!)
Measuring tape or a ruler
Pins or sewing clips
Tailor’s chalk or a washable fabric pen
An iron and ironing board
Optional: A seam ripper (if taking out old stitches)
Optional: A hump jumper or thick folded fabric

Why Special Tools?

Denim is thick fabric. Sewing denim needs tools that can handle it.

Denim Needle: A regular needle might break or skip stitches. A denim needle is stronger and sharper. It has a special tip to push through thick fabric easily. This helps avoid problems when sewing thick seams. Use the right size. A size 16 or 18 is good for most jeans.
Heavy Duty Thread: Normal thread can break when sewing denim. Heavy duty thread is stronger. It holds up better, especially when sewing thick seams at the side seams of the jeans. Use a color that matches your jeans thread, or a contrasting color if you like that look.

Get Your Jeans Prepared

First, wash and dry your jeans. This is important. Fabric can shrink the first time it’s washed. You want to work with the final size of the fabric.

Mark the New Length

This is a key step. Getting the length right is important so your shortened jeans fit well.

Try Them On

Put on the jeans and the shoes you will wear with them most often. Stand naturally.

Mark the Spot

Have a friend help you. Or stand next to a mirror. Fold up the bottom of one pant leg to where you want the hem to be. Make sure it looks good with your shoes. Use a pin to mark this spot on the outside of the leg. Do this on both legs.

Measure Your Inseam

The inseam is the seam that runs down the inside of the pant leg, from the crotch to the bottom hem. You can measure the inseam of a pair of jeans that fit you just right. Lay those jeans flat. Measure from the crotch seam down to the bottom edge of the hem. This gives you a target inseam length for the jeans you are working on. Write this number down. Now, measure the inseam of the jeans you are hemming. Subtract the target inseam from the current inseam. This tells you how much total length you need to remove from the bottom.

Add Space for the Hem

You need extra fabric below your mark to make the hem. This extra fabric is called the “seam allowance”.

For a Standard Hem: Add about 1 to 1.5 inches (2.5 to 4 cm) below your desired length mark. This will be folded up twice to create the hem.
For Keeping the Original Hem: You only need a little bit of space below the original hem to attach it to the shortened leg. Maybe 0.5 to 0.75 inches (1.2 to 2 cm). But this method works differently, which we will explain later.

Make Clear Marks

Take the jeans off. Lay them flat on a table. Use your measuring tape to measure from your pin mark down the amount you added for the seam allowance. Use your tailor’s chalk or pen to make a clear line all the way across the pant leg at this lower point. This is your cutting line for a standard hem. Do this on both legs. Double-check that the line is the same distance from the top of the waist on both legs. This helps keep the legs the same length.

Method 1: Standard Hem

This method cuts off the old hem and makes a new one. It’s a basic way to shorten jeans.

Step 1: Cut the Fabric

Lay your jeans flat. Make sure the front and back legs are lined up. Using your sharp fabric scissors, carefully cut along the lower line you marked. This line is your cutting line. Cut off the excess fabric from the bottom of both pant legs. You just cut off the old hem.

Step 2: Prepare the Hem

Now you need to create the folding jeans hem. This makes a clean edge that will not fray.

First Fold: Fold the raw edge of the fabric up towards the inside of the pant leg. Fold it up by about 0.5 inches (1.2 cm).
Press: Use a hot iron to press this fold flat. Iron jeans hem well. This helps it stay in place.
Second Fold: Fold the edge up again towards the inside of the pant leg. This time, fold it up by the remaining amount of your seam allowance (about 0.5 to 1 inch, or 1.2 to 2.5 cm). This hides the raw edge completely inside the double fold.
Press Again: Iron this second fold well. You should have a neat, clean edge at the bottom of the pant leg. This is your finished hem width.
Pin: Put pins around the hem to hold the folds in place. Place pins every few inches. Make sure the side seams of the jeans are folded neatly and match up on both sides of the hem.

Step 3: Sew the Hem

Time to sew on your machine.

Set Up Your Machine: Put in your denim needle. Thread your machine with heavy duty thread, both in the top and the bobbin. Set your machine to a straight stitch. A slightly longer stitch length is often better for sewing denim, maybe 3.0 to 3.5 mm. This helps prevent skipped stitches and makes the seam stronger. Set your tension correctly (you might need to test on scrap fabric).
Start Sewing: Place the pant leg under the presser foot. Start sewing near one of the side seams. Sew close to the folded edge, about 1/8 inch (3 mm) from the inside fold. Sew all the way around the pant leg.
Sewing Thick Seams: When you get to the side seams of the jeans, the fabric will be much thicker. The sewing machine might struggle. This is where a hump jumper or a small piece of folded fabric (like denim scrap) can help. Place it behind the presser foot as you approach the thick seam. This helps keep the presser foot level and lets the feed dogs move the fabric better. Go slowly over these thick spots. You may need to turn the handwheel slowly by hand.
Finish the Stitch: Sew all the way around until you overlap your starting stitches by about 1 inch (2.5 cm). Use reverse stitches for a few stitches at the start and end to lock the seam. This keeps the stitches from coming undone.
Repeat: Sew the hem on the other pant leg the same way. Make sure both hems are the same width.

Step 4: Finishing

Cut any loose threads. Give the hem a final press with the iron. Your standard hemmed jeans are ready to wear!

Method 2: Keep Original Hem Jeans

Some people like the look of the original hem on their jeans. It often has special stitching or a faded look that is hard to copy. This method lets you keep that bottom edge. It’s a bit trickier but gives a professional look.

Step 1: Mark How Much to Shorten

Put on the jeans and shoes. Fold the pant leg upwards towards the knee until the original hem is at the right length. Pin the original hem in place. Take the jeans off.

Now, measure the distance from the original hem (the bottom edge) down towards the knee. This distance is how much total length you need to remove. Do this on both legs. Double-check that this measurement is the same on both legs.

Step 2: Prepare for Sewing

This method involves folding the excess fabric up and sewing right below the original hem stitching line.

Measure and Mark (Again): Lay the jeans flat. Measure from the bottom edge of the original hem upwards towards the knee. Measure the amount you calculated in Step 1 (how much to remove). Make a line with chalk across the pant leg at this point. This line shows where the bottom of the new fold will end up.
Fold the Hem Up: Take the original hem and fold it upwards, towards the knee, right at the original seam line of the hem. The fold should happen where the original stitching is. This creates a large loop of fabric folded towards the inside of the leg. The line you just drew shows where the bottom of this fold should sit against the main pant leg.
Align and Pin: Align the fold so that the original hem sits at your desired length. Pin the original hem in place around the leg. Pin carefully, making sure the fold is neat and the original hem is even. The raw edge of the original pant leg is now tucked up inside this fold.
Another Fold (Optional but Recommended): For a cleaner finish inside, you can fold the raw edge of the pant leg (the edge that is now pointing upwards inside the folded hem) down by about 0.5 inches (1.2 cm) towards the hem before you sew. This hides that raw edge inside the fold, just like the first fold in the standard hem method. Press this fold lightly.
Final Fold Alignment: Ensure the original hem is folded up correctly and pinned. The folded edge of the main pant leg should line up with the mark you made in step 2. You are essentially creating a new fold line just above the original hem.

Step 3: Sew Near the Original Hem

This is the main sewing step. The goal is to sew a new seam just below the original hem’s stitch line.

Set Up Your Machine: Use your denim needle and heavy duty thread. Set your machine to a straight stitch. A shorter stitch length, maybe 2.5 to 3.0 mm, can help make the stitches look like the original ones.
Start Sewing: Place the pant leg under the presser foot. Position the fabric so the needle will sew just a tiny bit (about 1/8 inch or 3 mm) below the original hem stitching. This new seam will hold the folded fabric up and make the shortened hem.
Sewing Thick Seams is Key Here: You will be sewing through many layers of denim, especially at the side seams and where the original hem is folded up. This is where sewing thick seams is most challenging. Go very slowly. Use the handwheel if needed. Use a hump jumper or folded fabric scrap to keep the presser foot level when going over thick spots. Do NOT try to force the fabric through. This can break your needle or damage your machine. Patience is important.
Sew Around: Sew carefully all the way around the pant leg, keeping your stitches straight and the same distance from the original hem stitching. Try to keep this new seam about 1/8 inch below the original hem stitching.
Finish the Stitch: Overlap your stitches by about 1 inch (2.5 cm) and use reverse stitches to secure the seam.

Step 4: Trim the Extra Fabric

After sewing, you have a layer of extra fabric folded up inside the pant leg. You need to trim this away.

Turn Inside Out: Turn the jeans inside out.
Trim: Carefully cut the excess fabric away. Cut about 0.5 to 0.75 inches (1.2 to 2 cm) below the seam you just sewed. Be very careful not to cut the seam itself or the main part of the pant leg. You are just cutting off the large fold of extra fabric.

Step 5: Finish the Raw Edge

Now you have a raw edge of fabric inside the hem where you just cut. You need to finish this edge so it does not fray.

Zigzag Stitch: If your machine has a zigzag stitch, use it. Sew a zigzag stitch along the raw edge you just cut. This is a good way to stop fraying on sewing denim projects.
Serger: If you have a serger machine, you can use it to finish the edge. This gives the cleanest, most professional look.
Binding: You can also cover the raw edge with a strip of fabric (bias tape) for a very neat finish, but this adds more steps.

Step 6: Final Press

Turn the jeans right side out. Give the original hem a good press with the iron. Your jeans now have their original hem at a new, shorter length.

More Tips for Sewing Denim

Sewing denim is different from sewing cotton or other light fabrics. Here are more tips to help you get it right when sewing thick seams:

Needle Size Matters: We said a denim needle is key. For very heavy denim, you might even need a size 18. If your needle keeps breaking or bending, try a larger size.
Slow and Steady: Go slowly, especially over the thickest parts like side seams. Don’t rush your machine.
Check Your Bobbin: Make sure your bobbin is wound evenly and has enough thread. Running out of thread mid-seam is annoying, especially on a thick hem.
Test First: Before sewing on your jeans, test your stitch length and tension on a scrap piece of denim. Fold the scrap multiple times to copy the thickness you’ll sew through. This helps you see if the stitches look good and the machine can handle the layers.
Use Your Hands: Sometimes, gently guiding the fabric helps. Don’t push or pull hard. Let the machine’s feed dogs do the work. But you can help feed the fabric straight.
Clean Your Machine: Denim can create a lot of lint. Clean your machine often, especially the bobbin area and under the needle plate. This keeps your machine running smoothly.

Dealing with Problems

Sometimes things go wrong. Here are some common issues and how to fix them.

Skipped Stitches: This often happens when the needle can’t go through the fabric properly.
- Are you using a denim needle? If not, change it.
- Is the needle new and sharp? A dull needle struggles with denim. Change it.
- Is the needle the right size? Try a bigger size (16 or 18).
- Is your machine speed too high? Slow down.
- Is your tension right? Test and adjust.
Needle Breaking: This usually happens when you force the fabric, or the needle hits something hard (like a pin).
- Go slower, especially over thick seams.
- Use a hump jumper or folded fabric to level the presser foot.
- Remove pins before you sew over them.
- Use a stronger needle (denim needle, larger size).
Fabric Not Moving: The machine isn’t feeding the fabric forward.
- Check that the presser foot is down.
- Check that the feed dogs are up (the little teeth under the presser foot).
- Make sure you are not pulling or pushing the fabric too hard. Let the machine feed it.
- Make sure the presser foot is level, especially over thick spots. Use a hump jumper.
Uneven Hem: One leg is longer, or the hem is wider in some spots.
- Did you measure and mark carefully on both legs before cutting? Measure again from the waist down before sewing if needed.
- Did you iron the folds well and pin them before sewing? Ironing helps hold the shape.
- Were you sewing a consistent distance from the edge (standard hem) or the original stitching (keep original hem)? Watch your guide lines or the edge of the presser foot.

Take Care of Your Jeans

After hemming, wash and dry your jeans as you normally would. Check your stitching after the first wash to make sure it held up.

Final Thoughts

Hemming jeans is a useful skill. It lets you make your clothes fit you perfectly. Whether you choose a standard hem or decide to keep original hem jeans, your sewing machine is a powerful tool for the job. Remember to use the right supplies like a denim needle and heavy duty thread. Take your time when sewing thick seams. With a little practice, you can shorten jeans like a pro. Enjoy wearing your perfectly fitting pants!

Frequently Asked Questions (FAQ)

h4 Can I Hem Jeans Without a Denim Needle?

You can try, but it is not advised. A regular needle is more likely to break or bend when sewing thick denim. It might also skip stitches because it can’t push through all the fabric layers easily. A denim needle is made strong for sewing denim and other thick fabrics. Using the right needle gives better results and protects your machine.

h4 What is the Best Stitch Length for Sewing Denim?

For a standard hem, a slightly longer straight stitch (like 3.0 to 3.5 mm) works well. It makes a strong seam and looks good on denim. If you are trying to match the look of original hem jeans stitching, you might use a slightly shorter stitch (like 2.5 to 3.0 mm). Test on scrap fabric to see what looks best.

h4 How Much Fabric Should I Fold Up for a Standard Hem?

For a typical jeans hem, fold the raw edge up by about 0.5 inches (1.2 cm) first. Then fold it up again by another 0.5 to 1 inch (1.2 to 2.5 cm). This creates a strong double-folded hem. The total seam allowance you cut should be the sum of these two folds (1 to 1.5 inches or 2.5 to 4 cm).

h4 What is a Hump Jumper? Do I Need One?

A hump jumper (also called a jean-a-ma-jig) is a small tool that helps your presser foot stay level when sewing over very thick areas like side seams. It lifts the back of the presser foot so the fabric can move under it smoothly. You don’t absolutely need one, but it makes sewing thick seams much easier and helps prevent skipped stitches or broken needles. You can often use a folded scrap of denim or other thick fabric in a similar way.

h4 My Machine is Struggling with Thick Seams. What Else Can I Do?

Besides using a denim needle, heavy duty thread, and a hump jumper:
* Slow down your sewing speed a lot. Use the handwheel if needed for just a few stitches over the thickest part.
* Check your machine manual for tips on sewing thick fabrics. Some machines have adjustable presser foot pressure or other features that help.
* Make sure the fabric is flat and not bunched up as you approach the thick part.
* Consider using a heavier-duty machine if you plan to sew denim often.

h4 Can I Hem Jeans by Hand?

Yes, you can hem jeans by hand, but it is difficult and time-consuming because denim is so thick. You would need a very strong needle, thick thread, and a lot of patience. A sewing machine is highly recommended for hemming jeans.

h4 How Do I Measure Inseam Correctly?

To measure inseam on pants that fit well, lay them flat. Smooth out one leg. Find the seam where the two legs meet at the crotch. Put the end of your measuring tape right at the middle of this cross seam. Run the tape straight down along the inseam to the bottom edge of the hem. That measurement is the inseam.

h4 How Can I Make Sure Both Pant Legs Are the Same Length?

Measure carefully from the waistline or crotch down to your marking line on both legs before cutting.
After folding and ironing the hems, measure the folded hem width on both legs. Make sure they are the same.
After sewing, measure the finished inseam on both legs again to confirm they match your target length.