Squaring Up A Quilt Block

trimming quilt block edges

Oh squaring up quilt blocks…I’ve put off this post almost as long as I put off squaring up blocks when I make quilts. I have no idea why, but squaring up blocks is my least favorite part of quilting. Once it’s done I’m completely tickled, but thinking about doing it just makes me want to quit.

But that ends today! Today I bite the bullet and square up my quilt blocks and show you how to do the same. I’ll show you the traditional way of squaring quilt blocks, helpful tools, and a technique for when you think you’ve completely ruined your quilt (so don’t despair!).

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Helpful Tools for Squaring Up Quilt Blocks

There are two really helpful tools that will help you get perfectly square blocks. That said, they are not mandatory. All you really need is a rotary cutter, self-healing mat, and acrylic ruler.

A Ruler That’s the Same Size as Your Block

If you’ve got as many rulers as most quilters I know, odds are that you have a ruler that measures the same size as your finished block. If so, then your life is about to get pretty easy! Scroll down to the tutorial, and you’ll be on your way!

Stripology Ruler

This ruler is a great tool to have on hand for any sized block that comes along. It’s got multiple guides for your rotary cutter, which makes squaring up a breeze no matter what size quilt block you have.

How to Square Up a Quilt Block: A Tutorial

Now, we are on to the good stuff! There are two ways that your block can (and almost always will) go: you can have a block that’s too big, or you can have a block that’s too small. Before I go any further, I want you to remember that it’s a rare occasion that anyone’s block is perfect. Usually a perfect quilt block is the result of good technique and consistently squaring up blocks after they are sewn. Without further ado, I give you how to square up a quilt block:

Press It Again

Before you even think about trimming up your quilt block, make sure that you’ve pressed it and pressed it well. For tips on how to press well, make sure to check out my post on Pressing Quilt Blocks. I like to press my blocks a second time and starch them with Best Press before I square them up.

How to Square Up a Quilt Block That’s Too Big

1. Line It Up

This seems to be the most common problem in quilting. Maybe some pieces of your block measure to be just right, but there’s funny little edges that stick out here and there, or maybe the whole block is too big. Either way, you’ll start by placing your block on top of your cutting mat. If you’ve got a ruler that is the same size as your finished block, go ahead and center it on the block, making sure to line up your vertical and horizontal lines with the main seams on the block. This is also a good time to check and make sure that your 45 degree angle makes a nice line from corner to corner of the block.

how to line up a quilt block for trimming

If you’re using a ruler that is NOT the same size as your block, that’s fine. Start off with one corner of the block, line up your horizontal and vertical lines and seams and trim as little as needed to get two sides straight. You’ll use these two straight sides to reset your ruler in the same way to square up the other corners.

2. Trim It Up

Once everything is carefully lined up, go ahead and trim your block.

Note: If you have any shapes (especially triangles) on the outside edge of your block that will be trimmed down, make sure that you keep enough fabric to allow for a consistent 1/4″ seam! No one wants to chop the tip of their triangle off!

trimming quilt block edges

How to Square Up a Quilt Block That’s Too Small

Sometimes it happensโ€”your block is too small, or  a piece of your block is too small and you could just cry over the countless hours, fabric yardage, and cash that’s about to be wasted! But don’t worry, I’m here to help!

The Freezer Paper Method

What to do when your quilt block is too small

First, you’ll want to try this out: Cut a piece of freezer paper to the size that the quilt block should be. On the dull side, draw lines 1/4″ from all edges. This will show you your seam allowance.

how to use freezer paper to trim quilt blocks

Then draw a horizontal and vertical line down the center of the block (or wherever will be the most helpful guide). This will help guide you to where the center of the block should be and help you line up seams to be straight.

how to square up a quilt block that is too small

Last, draw a diagonal line from opposite corners.

Now, place the freezer paper on top of your block (shiny side down). Line it up, making sure that the freezer paper is centered on the block and everything looks straight. If the edges of your block fall within the 1/4″ border around the paper, you’re in luck! You can still make this quilt workโ€”iron the paper into place and make sure to LEAVE the freezer paper ON for now.

Wax paper for quilting

Repeat this process with the rest of your blocks.

With the freezer paper still attached, sew your blocks together, the raw edges of the freezer paper will act as the (perfectly straight) raw edges of your block. This will ensure that your blocks come together squarely, even though your seams might not.

When your quilt block it too small

Once all your blocks, rows, and borders are added, gently rip away the freezer paper.

That’s all there is to it! Make sure you pin this post and save it for when you need it most!

Practice your new skills on a new pattern!

A helpful guide for what to do when your quilt block turns out too small.


  1. Great tutorial! I’m getting more accurate in my piecing but this still happens occasionally. Now I don’t have to panic. Thank you!

  2. Thank you for this tip. Kind of what I have been doing without the freezer paper or starching. I think these two things will be very helpful in future.

  3. Brilliant! I’ve got a number of mis-shaped block with pesky points I need to square up. The freezer paper idea is the best!

  4. Awesome….thanks so much!

  5. Thank you, Rachel. I have recently stepped into the role of Tutor to a Beginners Class after only a few years since i began quilting myself. This is a problem I have encountered with my new students so i am delighted to find a way to help them “get it straight”. As I have not had this problem myself, I struggled to find a simple solution to save the frustration of either unpicking or redoing a wonky block. I am sure my friends will bless you for this ๐Ÿ™‚

  6. That is very helpful. Iโ€™ve found myself needing to fix that problem too many times

  7. Love this tutorial! I would just like to clarify when using the freezer paper on a block thatโ€™s too small, does it get pressed to the right side or the wrong side of the block? Thank you!

  8. Great tutorial. Simply easy to follow and very helpful. Thanks.

  9. Great tips. I am new to quilting. Can you please tell me what freezer paper is. Iโ€™m in Australia, an Iโ€™m not sure what you mean. Thank you ๐Ÿ˜Œ

  10. HiRachel, thank you for all your brilliant advice. I am a beginner and after watching lots of videos and reading many blogs I am confused about trimming the blocks. Do I need to trim all my square blocks before piecing my quilt top together? Many thanks from Scotland ๐Ÿ™

    • Thanks for your comment, Lorraine.

      Yes, I suggest trimming all blocks after sewing them and before piecing all blocks together. It makes for a really square quilt that you’ll be happy with! ๐Ÿ™‚

  11. Hi. Just wanted to make sure your readers are aware that freezer paper shrinks a bit on first ironing. Would be advisable to preshrink the paper by ironing before cutting the templates.

    • Good tip, Christine! I typically cut loosely around my templates for the first time through and then trim it once it’s been ironed a whole bunch of times, but if you like to trim beforehand, it’s definitely something to keep in mind.

  12. What will keep my too small quilt black from pulling away at the seem if there is only about 1/8 inch left in the seam allowance? Would it work at all for me to take a little bit deeper seam if I do it on all the pieces in the quilt?

    • Hi Mary,

      Great questions! Taking a deeper seam *should* work, but you must be consistent in all your pieces. Not knowing exactly what quilt you’re working on makes me hesitant to say that, but generally, if your seam allowance is consistent throughout the entire quilt, then you should be set!

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