How to Sew Mitered Cornersfor Perfect Hems

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Learning how to sew mitered corners is one of the best ways to create professional-looking hems with sharp, neat corners. Mitered corners reduce bulk where two hems meet, allowing items such as napkins, tablecloths, quilts, curtains, and placemats to lie flat and look beautifully finished. There are several ways to sew mitered corners, and the best method depends on the width of your hem and the look you want to achieve. In this tutorial, you’ll learn three easy methods for sewing mitered corners, including narrow hems, wide hems, and decorative bias tape finishes.

How to Sew Mitered Corners(Quick Guide)

Mitered corners create a neat 45-degree corner that reduces bulk and gives hems a professional finish. The basic method involves pressing the hem allowances, marking a diagonal fold line, trimming away excess fabric, and then refolding the hem before stitching.

Press the hem allowances on all sides
Open the folds and mark a diagonal line in the corner
Trim the excess fabric and fold along the diagonal
Refold the hem allowances
Pin the corner securely
Topstitch around the hem

When to Use Mitered Corners

Mitered corners are used when two hems meet at a right angle, and you want a neat, flat finish without excess bulk. They are commonly used for:

Napkins
Tablecloths
Placemats
Quilts
Curtains
Table runners
Lightweight blankets
Decorative home décor projects

Mitered corners work best on fabrics that press well, such as cotton, linen, quilting cotton, canvas, and lightweight denim. Read the complete guide to sewing hems for more hem types for different fabric.

How to Sew Mitered Corners (Step by Step)

There are 3 main methods of how to sew mitered corners. Both these methods should be used for light to medium weight fabrics that are able to be pressed. It is not suitable for really heavy fabrics (unless you make a very wide hem) and polyester type fabrics that won’t easily press. Cotton, Linen and denim fabrics work really well. In addition, sewing mitered corners can be done with bias tape. See the end of this article for this additional method.

Method 1 has just a folded corner and is suitable for narrow hems such as those found on napkins and scarves.
Method 2 has the corner sewn on the diagonal and is best for wide hems such as those found on quilts and tablecloths. You can see in the photo how the wider hem is sewn shut on the diagonal at the corner.
Method 3 uses bias tape and is great where you want a contrast fabric hem.

A folded mitered corner is best for small hems such as those used on napkins and tablecloths.

How to Sew Mitered Corners Video Tutorial

Watch the video and follow along with the step by step instructions

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Step 1 – Press the Edges

On the wrong side of the fabric, press over one edge by a 1/4″ (6mm) to 1/2″(12mm) and fold and press all around the edges. Now fold and press a second time by the same amount to create a double hem.

(I created 1/2 inch (12mm) hems so you could see my sewing, but smaller hems look much neater at the corners.)

How to Sew Mitered Corners - Folded Corners

See how the hems cross over each other in the corner. You might need to press a couple of times in the corner to get it to sit relatively flat. Don’t obsess about the corner too much, but a bit of water spray helped a lot with this denim.

Step 2 – Mark the Diagonal

Open the folds, and you will see creases around the edges with two parallel lines forming a square in the corner.

Take a fabric pen and mark a 45-degree diagonal line through the center of the square.

To make it clearer in the photograph, I have marked the creases with a pen. You don’t need to do this unless you are also having trouble seeing the creases. In real life (rather than a photo), the creases are normally extremely obvious.

Step 3 – Cut and Press

Cut across the first diagonal line and mark another diagonal line through the inner corner of the square.

Press a hem along this marked diagonal line. Do not sew this hem as it is a folded hem only.

Step 4 – Refold the Hem

Fold up your pressed edges again and secure the corners with a pin on each side. Repeat this for all the other corners.

Sorry the hem photo is a bit blurry. I got distracted and the autofocus focused on my cat! She was really cheeky that day and kept grabbing my fabric before promptly falling asleep on my work table.

Step 5 – Stitch the Hem

Topstitch all the way around the hem edges.

BEGINNER TIP: Get a nice sharp corner by stopping with the needle down and then pivoting.

This folded, mitered corner is perfect for any project needing sharp, neat corners.

Sewing Mitered Corners Variations

Wide Mitered Corners

This follows the same principles, but some stitching across the corner makes the difference and is a better method when you want a wider hem. Press over your edges by 1/4″ or 1/2″ (6-12mm). Press over the hem a second time by your desired amount.

An example: I am using a seam allowance of 1 1/2 inches (3.8cm) and have divided my hem into 1/4 inch (6mm) for the first fold and 1 1/4 inch (3.2cm) for the second fold.

Your preferred size will depend on the article as you may require a narrow hem for napkins, but a bigger and bolder hem for curtains. Repeat this and press firmly on all corners. A bit of spray water can help with stubborn fabrics like this medium-weight denim.

Open up the hems to show the second crease lines but keep the narrow first crease folded down.

Draw a diagonal line across the folded inner corner at 45 degrees. See how it passes edge to edge and through the intersection of the inner creases.

Fold the marked corner in half with right sides together. This will form a triangle. Pin this together making sure the marks connect exactly at the edges. Machine stitch along the marked line with a backstitch at the start and finish.

Carefully trim off the excess fabric across the corner about a 1/4 inch (6mm) from the stitching line. This will reduce bulk in the corner.

Turn the corner to the right side and push the point out gently. I generally just use the point of my scissors but just be careful not to push too hard.

Press your miter corner and the rest of the hem ready to be stitched. If you are using a difficult to press fabric, a spray of water might just help.

Pressed and ready to go, machine topstitch around the article to complete the hem. Nice and neat isn’t it?

Sewing Mitered Corners with Bias Tape

Bias tape can also be used to sew a mitered corner. It does take a little longer to sew but is perfect for when you want a pop of color on the edge. Use 1/2 inch (12mm) double-fold bias. Further Reading: How to Make Bias Tape

Open the wider edge of the bias and place it on the wrong side of the fabric edge. Stitch in the crease which will be approximately 1/4 inch (6mm) from the edge. Stop 1/4 inch (6mm) from the corner and backstitch.

Fold the bias around the corner. Make the corner tight. This will result in a crease of fabric on the diagonal.

Stitch 1/4 inch (6mm) from the edge and continue in the crease along the next side.

Fold the bias corner back over the edge to the right side. If you have more than one corner continue in this way for all corners. Read how to sew bias tape if you need more tips on sewing overlaps.

Use pins or fabric clips to hold the bias tape in place on the right side of the fabric. The corner will be folded into a 45 degree diagonal angle. Use an extra pin at that point. Stitch along the edge of the bias.

Pin for Later

Common Mistakes When Sewing Mitered Corners

Choosing a Hem That Is Too Narrow – Very narrow hems can make marking and folding difficult. Practice on scraps first if you are new to mitered corners.
Not Pressing Before Sewing – Accurate pressing creates crisp folds and makes the corner much easier to construct.
Skipping the Trimming Step – Removing excess fabric from the corner helps reduce bulk and allows the corner to lie flat.
Using Long Stitch Lengths on Corners – Smaller stitch lengths provide greater control when sewing around corners and diagonal seams.
Forgetting to Match Measurements – Uneven hem allowances can cause distorted corners and misaligned edges.

Sewing a Mitered Corner FAQs

What Is a Mitered Corner?

A mitered corner is a sewing technique that creates a neat 45-degree corner where two hems meet. It reduces bulk and produces a professional finish.

Are Mitered Corners Difficult to Sew?

No. Folded mitered corners are beginner-friendly, while sewn mitered corners for wide hems require a little more measuring and pressing.

What Fabrics Work Best for Mitered Corners?

Cotton, linen, quilting fabrics, canvas, and lightweight denim work best because they press easily and hold crisp folds.

Why Are Mitered Corners Used?

Mitered corners reduce bulk, help hems lie flat, and create a cleaner finish than overlapping folded corners.

In Conclusion

The choice is yours, now you know three simple but smart ways how to sew mitered corners that are sharp and neat. Use this as a quick reference

Method 1 – best for narrow mitered corners and hems
Method 2 – best for wider hems
Method 3 – best where you want a pop of color on the edge

Now you know how to sew mitered corners, make yourself some napkins. Homemade napkins don’t need much fabric and are sure to impress your guests. Match your home decor and special occasion. These linen napkins are made with method 1 which is the narrow mitered corners making them simple and easy for beginners.