Square up Your Quilt Blocks–The Right Way!

by Lorie on July 29, 2009

I know–I’ve been holding you hostage for a month now, waiting for this information.  After all I’ve put you through, you won’t believe how truly easy it is to square up a quilt block.  I’ve given you all the shameful squaring stories I’ve heard and I’ve given you some tips.  Now–here are the steps you take to perfectly square a quilt block!  Ready? 

First, I want to remind you of a few things:

1.  Use a squaring ruler.  It can either be square or a triangle, as long as it is larger than the block.

2.  As you square, be sure to visually square the center of the block in addition to squaring the edges.

3.  If a block is too small to square to the needed size, either do a new one, or add fabric to the edges of the block, and then square it. 

4.  Always square two edges at a time. 

How to Square a Quilt Block:

Step 1:  Lay the block on your cutting mat with the two sides you wish to square first on the bottom right.  Lay the ruler over the block, with the correct blockmeasurement in the upper left corner of the block.  For this example, we chose 8″.   Adjust the ruler over the block until 1) the block is visually centered and 2) the edges of the block slightly exceed the upper left corner measurement. 







Step 2:  Using a rotary cutter, cut the right edge of the block first and then the bottom edge.  This gives you a perfectly square corner. 










Step 3:  Flip the block so that the just-cut corner lines up exactly with the final block measurement on the ruler and the edges of the fabric are matched to the correct lines on the ruler.  (In this case, 8″).  Check again to be certain the center of the block is visually square.  Cut the right side, and then the bottom.








If your block is put together correctly, and if you follow the above procedure, you should end up with a perfectly square block.  But, what if something goes wrong?

Q:  What if the edges of the block don’t exceed the block measurement?

A:  Measure the block through the center, going both vertically and horizontally.  If either measurement is less than the block size you put together, discard the block and do a new one.  Tip:  Use scant 1/4″ seam allowances when sewing to ensure your block comes out the correct size.  Keep in mind that all blocks have 1/4″ seam allowance built in.  If the measurement is just slightly below the desired size, you can square to the nearest 1/8″ and use a 1/8″ seam allowance.  This can be risky, particularly if you forget that the block is too small by the time you sew it into the quilt, or if the block frays after you sew it. 

Q:  What if my block exactly equals the finished measurement, but it still not squared?

A:  If the block is only slightly off, you can attempt to square it by taking off 1/16″.  If you do this, I suggest marking the correct sewing lines on the edges of the block with a soluable marker and sew it as soon as possible to avoid forgetting that the block is slightly too small.  You can also try pressing the block with starch or a starch alternative to ensure the seams are all lying flat.  Then, re-measure. 

Q:  What if the block is hopelessly too small, but I don’t have any more fabric?

A:  Make a smaller quilt.  Just kidding!  You can make a smaller block and adjust your measurements throughout the quilt but this can be really challenging.  Keep in mind that you would have to consider all the rest of the blocks, any sashing, borders, and binding in your adjustments.  If all of the blocks are too small, you can also square them to a smaller size and then add fabric strips to each side of the block.  Then, re-square the block using the side strips to the correct measurement.  This way, you can keep the block, add in a new fabric to the mix, and make it look like it was planned!

Hope this information is helpful to all of you guys, as it was to me when I discovered all of it.  I’m not the most accurate of sewers, so figuring out how to do this was essential to my quilting success.  Sorting through methods and practicing (Otherwise known as tossing blocks I squared incorrectly) has helped me eliminate the instructions that don’t work and get to the process that does.  I’ve also learned to always buy a little more fabric than I need, just in case I need to make a new block. 

Let me know how your squaring is coming! 

Sew Now, Quilt Now! 



1 Rachel 07.30.09 at 11:08 am

This is wonderful! Thanks so much for the information and the tips-they’re great! I’ll be linking to this.

2 Kris 07.30.09 at 11:46 pm


You are such a wealth of information! This article is absolutely fantastic! Thank you for all you share with us.

3 Amanda 08.01.09 at 12:57 am

This has been so useful, I’ve never been able to square my blocks properly, so I’m off to buy a larger square ruler. Could you possibly now do an article on squaring a finished quilt top please – I can never seem to get them accurate.

4 Kate 08.01.09 at 6:31 am

I appreciate the information, however, I have one safety concern and that is the way the cutting is done. Instead of trimming the right and bottom edges as shown, isn’t it safer to do the right and top edges? the way the instructions are written, I’m cutting into the bottom edge and the rotary cutter is BELOW my left arm – if the rotary slips or my attention is drawn elsewhere, I’m in danger of cutting my left arm. By doing the right and TOP edges, if the rotary slips there is nothing in the direct path of the blade that I can cut. this can be corrected by turning the block and ruler 90 degrees counterclockwise. (PS – can you believe that I was a safety program coordinator in a former life?)

5 Karen 08.01.09 at 10:39 am

I appreciate this information soooooo much! It is exactly what I was taught some years ago, however its one of those pieces of information that have been put into a brain cell and I’ve lost the”path” to that brain cell! Anyway, as soon as I read this it all came back. I concur with Kate though . . . wouldn’t it be easier to do the right and top of the block? I’m not as concerned about the safety aspect (I just a Fiskars rotary cutter and it has a shield on the top) but it seems awkward to be cutting the bottom of the block — I recall thinking that when I was taught to square blocks at the workshop I attended. I’m looking forward to your response to our questions. Thanks again for such clear instructions!

6 Karol 08.01.09 at 2:30 pm

There are as many ways to do things as there are quilters….but you did ask (lol)

a tip on rulers is to use rulers made by the same company throughout the project. All rulers may not be created equal but those from the same manufacturer should be the same throughout the line.

The width of a line on the ruler multiplied by all the seams in the blocks can put you out quite a bit out over the width and length of the quilt, so be sure you cut from the same spot on that line for every piece.

A hint to help you hit the right mark every time is to put a long piece of the thick, colored vinyl strips, sold to help you see the right line, on the Bottom of the ruler instead of the top. Place it at the width you want to cut so when it touches the previously cut edge, you will be lined up to the cutting line perfectly every time to cut the next piece. It will save you a lot of time on each piece you cut because you won’t be looking for just that right place every time. Especially good when you are using fractions of inches. You can also use a few layers of masking tape, moleskin or anything that will make a ‘fence’ on the ruler to rest against the fabric you are cutting.

When squaring a block lay a line of your squaring ruler on the line of a horizontal and vertical seam in the interior of the block as well to help squaring the edges.

As you said – Forget the freezer paper, it stretches. However you can preshrink it and then you can use it. Sharon Schamber, multi award winning quilter, does that. She has lots of videos on her sites


7 pam 08.03.09 at 7:42 pm

This is going to be a huge help. Thank you so much.

8 Carri 09.16.09 at 9:13 pm

DING! The lightbulb just went off over my head. I’ve been lining up, cutting the right side, then turning and cutting and turning and cutting….

thanks for the article!

9 Kathy 01.16.10 at 12:41 pm

I’ve been searching the internet for info on squaring and sizing quilt blocks. I’ve completed my courthouse steps blocks, which should have turned out to be 16 1/2″ blocks. Unfortunately, (being my first quilt) most of them are only 16 1/4″. My plan is to simply downsize all of them to 16″. The quilt will only be 2 1/2″ smaller! I have a 16″ square ruler. The quandry is, where on the quilt block to square it up? The top and bottom outside ‘logs’ are the same color, the outside side logs are also the same, but different than the top and bottom ones. Therefore, it seems to me these side logs are the crutial ones, they need to match when I join the blocks, and as long as all the blocks are the same size, and I can stay with a CORRECT 1/4″ seam allowance, it should work!
Any input?

10 Jeanine 03.08.10 at 12:15 pm

Thank you! I am working on a churn dash and so far, my blocks are not square, they are uneven. I bought a 12 1/2″ ruler and have been obsessing about how to use it to square the blocks that I so carefully cut, sewed with 1/4″ foot, and pressed so carefully. STILL not square. I hope this method works. Thank you again.

11 Anna 04.07.10 at 8:26 am

Your article on squaring a blcck has cleared up some questions I’ve had for sometime now. Now I can have an idea on how to deal with issues when they come up. Thanks again Lorie!

12 Alison Marie 07.13.10 at 4:27 pm

Great text in this article, but the photos links don’t seem to be working right now.

13 Debby Benson 08.15.10 at 8:18 pm

Thanks so much for this helpful information. I know I have this information somewhere in my sewing room, but it would have taken me forever to find it.

Comments on this entry are closed.