How to Square Up a Quilt

Once you finish quilting your quilt, before sewing the binding on, your next step is squaring up your quilt. In this post, I’m sharing the best process for how to square a quilt top. You can use the steps outlined to get crisp and beautiful corners for your finished quilt. And you don’t need a square ruler!

WHAT IS SQUARING UP A QUILT?

Squaring up a quilt simply means each corner of your quilt is a square 90° angle, and all the quilt sides are trimmed straight. The process I share here is called squaring.

DO YOU NEED TO SQUARE UP A QUILT?

Recently, one of our new Make Modern Triangle Club members, Janet S, reached out for help with making the sides of her Scrappy Whirligig/Modern Triangle #47 quilt straight.

Side note: look how pretty Janet’s quilt is! Squeeee! Pretty in Pink!

So, Janet? This blog’s for you!

Don’t Waste a Good Edge

First of all, I must ask, “why waste a good zig zag? Or a good wonk? If you’re working with a zig zaggy pattern like Janet’s or a wonky funky improv quilt, don’t feel like you must conform to perfectly square corners and straight edges.

For example, my Hexy Plus quilt features zig zaggy edges and I wouldn’t have it any other way!

I wanted to give you some ideas and permission to explore designs beyond the square. The rest of this post shares tips and information for all things square and straight edge. But if you’re looking for more ideas for fun and interesting edges, you can read this blog for inspiration.

DO YOU SQUARE A QUILT BEFORE OR AFTER QUILTING?

Typically quilts are squared after they are completely quilted and before attaching the binding. When you quilt your quilt, or have it quilted by a professional longarm quilter, the backing and batting will be larger than the quilt top.

Usually, if you’re doing it the “right” way, you’ll have at least 4” of batting and backing fabric extending beyond the top.

Once your quilt sandwich is completely quilted, you’ll want to square up your quilt top to square up the project but also to get rid of the excess batting and quilt backing before binding.

Now, I work with a lot of wonky edged quilt designs, so I usually square up my quilt top before quilting. And then after it’s quilted, I do do another trimming because sometimes the quilting process warps the project a bit.

DO YOU HAVE TO SQUARE UP A QUILT BEFORE ADDING BORDERS?

On a related note, did you know you’re supposed to square up a quilt before adding borders?

I know I know, another “should” that might stand in your way of finishing your quilt. Now I don’t want to “should” on you, but you probably would like to know what happens if you don’t square up before adding a border.

So, yeah, it’s actually an important step because if you don’t do it, you might end up with a quilt top that won’t lay flat. Orrrr you might get some bubbles when you quilt it… So yeah, it’s maybe annoying but an important step.

And you must know, sometimes I skip this step. But I usually regret it, ha!

HELPFUL QUILT NOTIONS

If you’re ready to square a quilt, then at this point in your quilting journey you have all the notions you need. (Probably. I don’t wanna assume… but if you’re curious I’ve got my favorite notions curated in my shop.)

For best results, you’ll want a large space where you can lay out your quilt sandwich as flat as possible. For me, that means cleaning off my work table or a large table. Anddddd that means just moving all the clutter to a different surface, ha!

You’ll want to use your large cutting mat.

Bonus tip, don’t get rid of your old worn out cutting mats. I keep my old ones under my bed and bring them out anytime, I’m squaring up a large quilt. But, if you’re like me, you’ll need to dust that baby off! (Lots of dust bunnies under my bed… ahem!)

And you’ll also need your largest rulers. If you’ve got a large square acrylic ruler, that’s even better. I typically just use my 6” x 24” acrylic rulers.

Finally, you’ll need the star of the show: your rotary cutter.

THE BEST WAY TO SQUARE A QUILT

I’ll show you my process for squaring up a quilt by showing you a recent finish, my Wildflower quilt. Before diving into the tutorial, notice that this quilt just needs the sides trimmed up, as the top and bottom edges are already straight.

STEP 1: START BY SQUARING A CORNER

To get started, layout your quilt top or quilted quilt sandwich on a large flat surface. Smooth out your quilt top as best you can and position your cutting mat underneath the first corner.

Use your rotary cuter and large square ruler to make a quilt corner 90 degrees. If you don’t have a square ruler just use a longer ruler or two rulers. I usually will use two 6”x24” rulers if I don’t want to dig out my large square rulers.

In the above picture, I’m showing the first trimmed corner for my Wavelength quilt top, which I squared up on my large dining room table. I squared up before quilting, because the edges were very much uneven due to the piecing construction.

STEP 2: TRIMMING THE FIRST EDGE

Once you have the first corner squared, you’ll follow the newly cut edge and continue trimming the first side of the quilt to cut all the uneven edges. Before using your rotary cutter, smooth out your quilt top so that it lays flat.

You can see from the below picture, I’m lining up the edge of my long ruler with the previously cut edge and the outer edge of the shortest fabric strip toward the top of my ruler.

You can also use the cutting lines on your cutting surface to trim in a straight line.

Now, you’ll be like Dory and just keep swimming. Except you are a quilter and you will just keep trimming!

You can see from the below picture, I’ve adjusted my quilt top with the edges straight on top of my cutting mat and the quilt top is smoothed out.

Finally, you’ll adjust your quilt top or finished quilt sandwich so that the next corner is on top of the cutting mat. Now you’ll line up the long ruler (or square ruler) with the side AND the top side.

By doing so, you’ll be able to get a nice 90° angle for corner number two. And if you want to use your big square ruler for this next corner, now’s a good time.

Then trim and voila a beautiful square corner!

STEP 3: REPEAT AROUND ENTIRE QUILT

To get square quilt corners and straight edge sides, continue this process to trim for all four sides and all the corners for your quilt.

Below you’ll see the images of me trimming the left side and each corner of my Wildflower quilt.

You can see I don’t use a large square ruler when squaring up a quilt. I can still get straight sides! Just take it one corner at a time and double check before you trim your rotary cutter.

Last but Most Important Step

And then don’t forget your last step. “Ta da!” Admire your work. Look at those square corners! That beautiful quilt! You did a great job! Now you’re ready for binding!

SPECIAL NOTE: PAY ATTENTION TO ANY POINTS ALONG THE EDGES

Before wrapping up, I want to give a special shout out to quilts featuring a design with points along the outer edges. For these beautiful quilts, you want to take special care not to trim the points off.

For example, Wildflower Star quilt (I promise the same names are a coincidence! But I guess I need to branch out!) features pretty colorful stars with points along the edges.

Below, you can see the project as I worked on it and you can see that the edges are not straight.

When you square up these quilts, make sure to leave a quarter inch seam allowance for your pretty points. Personally, I prefer to leave a generous quarter inch. I’d rather leave a gap of background than nip a point!

Below you can see what the quilt top looked like with a trimmed straight edge.

In the close up shot of the trimmed edge, you can see my generous seam allowances a bit more clearly.

I’ll also add, for my quilt tops I care more about to not trim off my points than I do a perfectly square quilt top. So whenever I square up a quilt with points, I start with the points versus starting with a corner.

This little pillow debuted in Issue 11 of Love Patchwork & Quilting Magazine. You can read more about it here.

NEXT STEPS & FREE CLASS

I hope you’ve found this article about how to square up a quilt helpful and informative!

As with anything, there’s no one right way to do anything, so as you’re reading this and thinking about your own quilting process feel free to take what works for you and ditch the rest.

If you have more tips, we always want to hear those. So please leave a comment to share your tricks and tips.

And once you’re ready to bind your quilt, check out our 25 Creative Ways to Bind your Quilt post or our favorite machine binding tutorial.

Get the “Outshine Star” pattern free when you take our Free Class

If you’d like to make your own quilt complete with zig zaggy corners like our member Janet S., then you can find the pattern inside our free, “Outshine Star” Modern Triangle Class. You can learn more and register here.