How to Sew Mitered Corners – 2 Ways

Making sure corners are exact, neat as a pin and professional is achieved with the mitered corner. In the sewing world, a miter is a simple technique used to finish the 90-degree corners of items such as quilts, napkins, tablecloths and curtains. Follow these easy steps to learn how to sew a mitered corner in two different ways.

In case you were wondering – Depending where you live in the world, you may spell it as miter (US) or mitre (UK, Australia). These are both the same thing.

How to Sew a Mitered Corner

There are 2 main methods how to sew mitered corners. Method 1 has just a folded corner and method 2 has the corner sewn on the diagonal.

As a general rule, use method 1 for narrow hems and method 2 for wide hems.

Method 1: Folded Mitered Corner.

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

Step one: On the wrong side of the fabric, press over one edge by a 1/4″ (6mm) or 1/2″(12mm) and fold and press all around the edges.

Then fold and press again a second time by the same amount to create a double hem.

See how the hems cross over each other in the corner.

Step two: 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.

Just so you can see it more clearly, I have marked the folds with a pen. (You don’t need to do this.)

Step three: 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 – it is a folded hem only.

Step four: 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 taking photos of my cat!

Step five: Topstitch all the way around the hem edges.

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.

Method 2: Sewn Mitered Corner

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.

Step one: 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.