Quilting 101: how to square up a quilt block

Quilting 101: how to square up a quilt block

Ever sewed a quilt block that was supposed to be square…but didn’t turn out that way? We guarantee it’s even happened to some of the quilters at Martingale! Less-than-perfect cutting and sewing can result in too-big or too-small blocks that refuse to lie flat when sewn together. Frustration soon follows.

Squaring up your blocks before you sew them together can help blocks fit together better, and it only takes an extra moment or two per block. Here’s a quick tip for how to square up a too-big quilt block from Quilts from Sweet Jane author Sue Pfau. (Look for help with too-small blocks in an upcoming post).

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How to square up too-big quilt blocks

When you check the desired measurement of an unfinished block and then trim any overlarge blocks to that size, your blocks will sew together nicely and your quilt top should lie flat. You can measure and trim sections of your block before assembling the full block, or you can trim the full block after you’ve joined its sections.

Use both the vertical and horizontal lines on your rotary ruler to ensure you are trimming the block squarely. You may have more excess on one side of the block than the other, so you should never trim the edges without determining where any excess lies.


When squaring up a block, first find its midpoint. For example, if you have a block that should measure 10″ square but it’s a bit large, place the 5″ intersection of your ruler where the block center should be. Trim the right and top edges. Rotate the block 180 degrees and align the 10″ lines of your ruler with the newly cut edges of the block. Trim any excess fabric.

BONUS TIP: It’s always a good idea to make one practice block before starting your project. You can do this with extra fabric from your project or fabric from your stash. Making a practice block helps answer any questions you may have about measurements, cutting, how the blocks go together, etc. If you make a mistake, you will see it and be able to fix it before it’s repeated throughout your quilt!

Projects from Quilts from Sweet Jane
From Quilts from Sweet Jane—most projects use one set of precut fabrics plus a neutral background fabric.

Quilts from Sweet JaneSee more from Quilts from Sweet Jane >

Print book (with free eBook): $16.99
eBook: $11.99

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Seamingly ScrappyWant more precut-friendly ideas?

Create a wonderfully varied collection of scrappy-looking quilts—all made the Seamingly Scrappy way! Choose from 10 innovative quilt patterns that rely on fat quarters, fat eighths, 2½" strips, and 5″ and 10″ squares. The Seamingly Scrappy technique works for traditional and modern styles, so you can let your favorite fabrics shine.

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How do your quilt blocks usually turn out: a bit too big, a smidge too small, or just right? Tell us in the comments!

28 Comments (leave a comment)

  • My blocks usually turn out just right. I’ve learned a lot of tricks to improve my accuracy. When assembling blocks (or medallion sections) into a top, the final measure usually is almost always less than a quarter inch off intended. For me, it is more fun to press, cut, and stitch with a little extra care on the front end than to square up and adjust a lot afterwards.

    Glad I found your blog! Thanks for sharing.

    Melanie McNeil on January 12, 2015
  • I just pieced together two twin-size quilts composed of six-inch square foundation pieced blocks. the vast majority were "just right" and I had a couple that were just a smidge small. I was able to adjust to fit them in and they all lie flat.

    —Janet G on January 12, 2015
  • Sometimes my blocks would be too big, other times they would be too small. A year ago, I bought a new sewing machine. I can make the most accurate 1/4″ seam allowance ever! So now my blocks come our perfectly everytime….I have even become braver at piecing triangle blocks…that was always frustrating without accurate 1/4″ seams.

    Cheryl Zehms on January 12, 2015
  • My blocks nearly always end up a bit smaller than the size the pattern states. It seems no matter how careful I am making my scant quarter inch seam I always have blocks a bit small. It seems to help if I press the seams open rather than to the dark fabric. I make them work but I am somewhat of a perfectionist so not having exact size blocks frustrates me somewhat.

    —Carol Zanzinger on January 12, 2015
  • My blocks used to always turn out too small. Then I learned how to move the needle on my sewing machine to make my seams a scant quarter inch. ((4 clicks to the right on mine). Now they come out nearly perfect every time!

    —Sandy on January 12, 2015
  • Some of my blocks turn out just right while others are just a sliver to large.

    —Marsha Nelson on January 12, 2015
  • My blocks come out perfect just often enough so that I know it CAN be done, but most of the time they are a bit wonky–hair short on one corner and a little over on the other. I have been known to find my smallest block and trim the rest down to that size-LOL There are always "creative opportunities" when I quilt !

    —lorna holley on January 12, 2015
  • No matter how hard I try to measure, cut and sew my blocks are usually smaller. I keep trying though.

    Sheila on January 12, 2015
  • If you are hesitant on making a test block because you don’t want to waste fabric…this is my remedy. I have a stash of dark,medium & light fabrics that are solely used for test blocks & eventually I have enough test blocks of the same color scheme that can be sewn together to form a quilt that is usually used as a donation quilt. Who doesn’t enjoy a sampler quilt.

    Dorothy I Dishman on January 12, 2015
  • My blocks are usually a little too small.

    —Pam on January 12, 2015
  • one thing I’ve found is pressing inner seams of block dry there is less distortion.

    Caroline Rohrer on January 12, 2015
  • Oh my goodness, all of the above. Frustrating some times, of course not when they turn out right but too big or too small can be irksome.

    —Patricia D. Roberts on January 12, 2015
  • Too large when paper piecing, too small when trying to do 1/4″ seams. Fortunately, paper piecing is intended for trimming after sewing a seam.

    —Lynne on January 12, 2015
  • Most of my blocks turn out fine. But those made up of many small units, especially triangles, often come out too small even though I use a scant 1/4″ seam. I’ve decided I should always make triangle units larger than called for and trim them to size.

    —Theresa on January 12, 2015
  • It also helps to use a thinner cotton, if your squares are a tad too small.

    Jeni Flemmer on January 12, 2015
  • My blocks usually are just right. I try to cut once, measure twice and rip if necessary for the right 1/4″ seam.

    —Linda Christianson on January 12, 2015
  • mine are usually a tad too big i have begun squaring them and it really is helping

    —Jo Goodloe on January 12, 2015
  • I’m very picky, so I make sure I have the right foot on my machine, and if not just right, I’ll use the seam ripper and do again…so pretty much come out 98% to 100% right…and the person who taught me to quilt, showed me how to square up my blocks and explained why in case they didn’t and would point out what I did wrong…so I learned early on…am so grateful to her!

    —Jeanette on January 14, 2015
  • Too small. I find most cutting instructions are for machine piecing, while I mostly hand piece. So trimming is a problem, too.

    —Ginna B on January 16, 2015
  • mine usually come out a tad too big which is great for squaring up.

    —cj on January 16, 2015
  • I guess I don’t agonize over the exact size as the pattern states, as long as all the blocks are the same size. Accurate seam allowances are ultimately the most important thing.

    —Karen Funk on January 16, 2015
  • Forgot to say thank you everyone for all the tips to help get the most accurate blocks.

    —Karen Funk on January 16, 2015
  • I try to remember the old adage – measure twice, cut once. If I’m careful, everything turns out pretty close to what it should. Maybe I have to square up a block or two, but that’s it.

    —Susan Clarkson on January 16, 2015
  • In my first quilt making beginning…ohm…however my blocks ended up being is how they were "fitted into my pieced top." Then, through her books, I "met" Eleanor Burns who showed me how to square off my blocks and why it was so important. I’ve been doing her method ever since including making sure my seam allowance is correct.

    Keep smiling,

    Lynnita Shipman on January 17, 2015
  • I have made several quilts in the past and I have found out that the bigger the square the easier it is to make them the same size weather it is cutting or sewing and now I’m working on squares that iare made up of 9 – 3 in squares . Although my small squares seem to fit together very well, it’s my lg squares that don’t

    —Cindy Rowan on February 9, 2015
  • When I finish blocks now they are usually the right size. I am currently going through projects I never finished which were started years ago. I really notice how my accuracy has improved but now need to deal with these blocks. A challenge is fun.

    —Heather on March 9, 2015
  • I find that trimming up oversized blocks to the size of the smallest a poor practice; especially if a dominate color on the outer edge of the block forms a secondary pattern in the quilt. Instead; when assembling blocks, I ‘square up’ as I build. This method does not involve trimming the outer edge away but rather using seam lines to even up sections of the block as I actually cut those sections. This method leaves all variances inside the seam allowances and will not show on the front of the block.

    —Sandee Heldt on March 19, 2015
  • I got frustrated with block size never being quite right and that was when I discovered applique. I also like embroidered blocks for my quilts. Both are much easier to get the right size.

    —Carol on January 26, 2016

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