Sewing Mitered Corners

Mitered corners look tidy and fancy. Most things we see (tea towels, table cloths, place mats and so on) have quickly finished edges. Many of them are simply a twice-turned (sometimes called “rolled”) hem, or a serged edge that has been turned and stitched. I call this a “serge and turn” if you can still see the serged stitches and a “serge and roll” if you can’t. If you are looking for a way to take a simple project up a notch.

Try making it with a wide hem with mitered corners.

Before I get started, I want to acknowledge that this may end up looking like a whole lot of words. Please take the time to read and then compare to the photos. This process is a wee bit counter-intuitive. I have sincerely tried to be as clear as I know how to be.

First off, you need to plan your project accordingly. I like to allow 1.25 inches for my hem when doing a mitered corner. This gives me a quarter inch to tuck under and one inch of fabric that shows off the miter. So I will add 2.5 inches to my desired finished width and length. For instance, if I want my table runner to be 12″ x 18″ when finished, I would cut out my fabric to measure 14.5″ x 20.5″.


Experienced sewers may be able to eyeball a quarter inch edge.

If you can do that, all the power to you! If you don’t think you would be able to do that evenly, or it would take you a long time to do so, I have a couple tips for you: If you have a serger, you can serge around the outside edge of the fabric. This gives you a quarter inch seam allowance that you can easily see and turn under. I encourage you to choose a thread colour that blends in with your fabric. This will hide any imperfections when you tuck the edge under and stitch it in place. If you don’t have a serger, you can run a row of stitching a quarter inch from the edge as a guide for turning your seam allowance. Use a thread colour that looks good with your fabric, that you can see, but that won’t look ugly if it shows a little after you are done. Both of these tips are optional, but they will make doing the corners much easier. There are presser feet that are designed to align a quarter inch from the edge of the fabric. If you don’t have one, they are a handy addition to your tool box.

You will need to mark your fabric in some way.

You will be marking on the right side of the fabric. You can use dressmaker’s chalk, a Pilot Frixion pen or other fabric marking pen.  If using a pen, please, please, PLEASE take the time to test it on your fabric before you use it. Frixion pens react to heat and marks should disappear when you press your project. But, I have had a few times when it didn’t completely disappear. I’m not sure whether it is an issue of fibre content or ink colour that causes this. Some fabric marking pens are water soluble and the ink washes away. I don’t have a lot of personal experience using the water soluble pens; both Dritz and Prym make these. I have many customers who swear by them. I usually use DM chalk or Frixion pens.

Marking the outer turn line:

Measure and mark your turn line 1.25 inches from each of your edges respectively. Do this on the right side of the fabric. You will end up with squares drawn on each corner.

Marking for the mitered corners:

Turn your fabric so you can work on the wrong side now. What you need here, is to mark the corners to prepare for the miters. If you have a grid ruler* use it to mark the 1.25″ lines at the corners; measure from the outer edge the way you did on the last step. Notice on my photograph that I marked the 1.25″ turn line about 2″ further than the corners of the squares. This is important. (*I highly recommend having at least a 4″x4″ grid ruler in your tool box. A 3″x18″ and a 6″x24″ are the other sizes I couldn’t live without. Olfa, Omnigrid and Fiskars all make very good grid rulers.)

Next, mark another set of lines 1 inch in from the lines you just made. Notice that this has created two more squares beside the corner square? These are important.

If you didn’t serge the edge, or stitch a quarter inch guideline, then take the time to mark where that quarter inch edge is now. You will thank me later.

Take a moment to notice what you have created. You should have 4 one inch squares drawn in the corner, with a quarter inch edge at the edge of the fabric. Think of that edge as being separate from your squares.

Now using a ruler (do not eyeball this) draw a line. Start at the point where the square meets the outer line at the edge of the fabric (2.25″ from the corner) through both squares and end at the outer line. You did not mark in the outer quarter inch. This creates a triangle with the corner of the fabric; it should bisect two squares. Your line should go through the point where the four squares meet in the middle. This is very important. This is your stitching line.


If you are doing this for the first time, I recommend that you just mark one corner to begin with. Once you have sewn it and you understand what it is you have to do, then mark the other three. That way, if you misunderstood the instructions on the first one, you don’t have to undo anything before you can proceed.

Creating the Mitre:

Fold your fabric at the corner with right sides together. You are creating a triangle here. You will be able to see your corner markings. Be careful to align all the edges accurately. You may find it helpful to pin the edges in place so they don’t shift while you are working. Line your work up so that the quarter inch edge is toward the back of the presser foot. Align the needle and presser foot with your stitching line. Your needle should be placed at the point where the stitching line meets the quarter inch seam allowance. DO NOT SEW OVER THE SEAM ALLOWANCE.

Secure the stitching by back tacking (sew forward and back a couple times) and stitch to the end of the stitching line. Secure the stitching again.

Trim the extra fabric away. Looking at the raw edge that you just trimmed, one end is the original edge of the fabric, the other is where the fabric was folded. Clip the fold from the edge to the stitching line.

Turn the corner right side out. Don’t press it yet because that would erase your markings. Use your finger or a point turner (another tool I couldn’t live without) arrange the seam allowance open. In other words, you want there to be seam allowance laying on both sides of the seam you created, inside the corner.

Once you have all four corners mitered, carefully line them up with the markings so they lay nice and flat. Press the corners. I recommend that you now press along the turn line all the way around the project. Take your time with this so that you get a nice smooth edge. If you chose a loose fabric, you should probably pin that edge in place at this point. Now you can easily turn that quarter inch edge under and top stitch as close to the edge as you can manage.

Ta-Dah! You just made a mitered table mat. Congratulations!