Today, we are talking about how to get accurate square in a square blocks (aka diamond in a square blocks). With many of my quilt patterns, you will notice that you will be directed many times in the pattern instructions to sew a triangle to a square, “being sure that your triangle is accurately centered.” That “accurately” part is what we are going to go over today!

Believe it or not, when I first started quilting, no one told me that it was important to measure my square before adding the triangle- I would just “eyeball” it and hope it turned out right! Even if you’ve got a good eye, you will get optimum results if you use one of the methods shown below to assemble your blocks. Yes, I know it takes a little extra time to do it this way, but you will be much happier with the results than if you just “wing it”…

The first way to do it, and the quickest, is the finger pressing method:

You will start with your square for the center (this could simply be a square of fabric, or it may be pieced, appliqued, or embroidered) and 4 triangles:

Fold the square in half and finger press to make a light crease. Unfold the square, and then fold in the other direction.

Now, use that light crease on the square to position your triangle with the top edge of the triangle lined up with the edge of the square, and the center point of the triangle lined up with the center crease of the square:

That’s the important part- make sure the your triangle point is lined up with the exact center of square! Don’t “eyeball” or guess at that part…

Your triangle will be **centered between the left and right sides**– it probably won’t be centered between the top and bottom edges. The left-to-right center is the only thing you need to worry about.

Now, if I could give you just one bit of advise for improving your piecing, it would be **Pin it! Pin it! Pin it!** I pin *everything- *even if I’m just sewing squares together into pairs or sewing strips together. It takes a little longer, but I feel that the accuracy you gain is well worth it.

You will also need to pin on the triangle on the opposite side of the square. You will need to get that first triangle out of the way so you can see your crease and get your second triangle lined up properly:

Sew your triangles to the square along the edge of the squre. Press out the triangles, being careful not to flatten the center fold- you’re going to need that crease for the next pair of triangles. Repeat the process for the next pair of triangles:

Sew on 2 more triangles. Press out the triangles:

and trim off “dog ears”:

While this method works well for a simple fabric square like shown above, the finger pressing method may not work as well for block center squares which are pieced or have been appliqued. For these types of blocks, I measure the center point with a ruler, and mark with a pin or with chalk, and then I position my triangles and pin them in place.

If you are following a pattern, the sizes for your squares and triangles will be given. But if you’d like to make some blocks on your own, and for those of you who have asked what size to cut your triangles, here is the formula that I use:

- Add .75 to your center square size (so, if your square is cut 6 1/2″ square, adding .75 gives you 7.25)
- Multiply by 0.7071 (so 7.25 x 0.7071=5.126, or 5 1/8″)
- This is the size to cut your square, which you will cut in half to make 2 triangles (so you would need 2 squares, 5 1/8″, to make 4 triangles for one block)
- If you would like, you can also round up 1/4-1/2″, and then trim the block when you are finished. So in this case, cut your squares about 5 3/8-5 5/8″ before cutting into triangles. This will give you a large seam allowance and plenty of “wiggle” room for trimming.

This technique is perfect if you are making my FREE pattern called Grammy’s Rose Garden – you will get LOTS of practice with your square in a square blocks!

I love granny’s garden I have a bundle of fabric just waiting to meet this lovely quilt pattern….also thanks for the tips. Can’t wait to start the next BOM!

Send me some photos of your quilt when it’s done, Karen! I’d love to see it!

Thanks for the how to on lining up the triangles. I am one of the “eyeballers”.

I can’t wait to make the quilt. Thank you for the cute pattern.

Thank you for the pattern I do appreciate it but why are the instructions not included.

Thank you so much for the great tutorial. I’m still not as accurate as I wish I was. I think I get in too much of a hurry. Thanks again! XO

Yes, Bev, I think we’re all in a hurry to get things done so we can move onto the next pretty project, right??

thanks Jackie, I have eyeballed in the past never again this way my squares will be 100% accurate, thanks for the tutorial and also the lovely quilt pattern

You’re welcome, Margaret! Hope this little tutorial helps :)

Thanks for the tut but it looks to me like you have gone over about 1/4 of an inch with the point. Is that so?

Sandy- now I see what you mean. My husband (a nonquilter) was confused as well! You only need to center from left to right- don’t worry about centering top to bottom. Does that make sense? I’ve corrected the blog tutorial. Thanks for picking that up!

I have always been an “eyeballer” and have had fairly good luck with that, but appreciate your tips here, and will try this the next time I make square in a square blocks. Thank-you.

Thanks so much for the tutorial — and the free pattern! The square in a square block is one of my favorites!

Thanks for the tutorial I am a new quilter, so I find your website very helpful. My question is are the triangles cut from the same size as the center square? Also could you explain more on your comment to Sandy Lowery about the point alignment as I don’t understand. Thank you

Your triangles will always be cut from a square which is larger than the center square- the instructions will tell you what size to cut your squares/triangles.

As for alignment, just line up the long edge of the triangle with the top edge of the square, then center the point at the bottom of the triangle between the left and right edges of the center square.

Thank you so much for the tutorial and the tip on pinning.

Thanks so very much Jacquelynne for explaining how this block works. I have always been afraid of making anything with this because I wasn’t totally sure as to how to do this one. I am quessing that this is the instructions for any size Square In A Square block. I am so looking forward to Cozy Afternoon.

Thanks for all your hard work so we can enjoy putting the beautiful creations together.

Great instructions for putting it together. I need to know the SIZE RELATIONSHIPS of the center square to the squares cut into triangles. You can’t just start with any sizes.

Thanks for prompt additional information about sizes to cut squares for triangles to make this block.

I love the way that you always share some kind of scripture and encouragement in your comments! I am encouraged and I get creative ideas that come to me and that is the Spirit of God using you Jacquelynne so keep up the great work!!!

I love you Sister!

God Bless YOU and may He continue to use you in our lives!

Big hug to you!

Karen

Jacquelynne, thanks for the tutorial, I’ll take any help I can get:) I’m wondering about the peacock feather fabric you used. Can you tell me the name? Thanks.

Colleen- that fabric was sold at a chain store (Hancock Fabrics, maybe??) a few years ago. I’m afraid it’s probably no longer available.

I definitely am an eyeballer, but no longer this will definitely help make my projects more accurate and professional.

I just found you through Pinterest. I would love to follow you. Thanks for the hints. I’m new at this.

I really love your website and the tutorial was so pretty!

I am new to quilting and love your website. You have such wonderful, helpful ideas. Thanks.

Hallelujah! Someone smarter than me thinks pinning is great too. So many people think it’s silly but it’s my bacon saver more times than I can count.

This Grammy pattern is just charming.

Yes- I spend a lot of time Pinning! There is very little that I don’t pin, even the most basic stuff. I think it makes a difference.

What a great tutorial maybe now with your help I become a better at making blocks on the machine.

Thank you so much I think it is a great quilt and one I never tried before.

Happy Quilting,

Yoka

I was an eyeballer for 9 of my 10 years of quilting I was shown one more step to the finger press hope you don’t mind if I share the square you finger press in the center edge same as you said next take the triangle and fold it in half right sides together finger press now square and triangle will sit together at the crease and still check that the point and center match

As a new quilter I always appreciate any tips and tricks available.

Hope you found it helpful!

I’m making this pattern with Tinkerbell fussy cut into the main squares. Using pinks and greens for the rest of it. For a special baby in Portland OR.

Love the look of it. Sort of an old fashioned look.

Thank you

Oh, my1 This is sew helpful, as I have never done one of these. Thank you sew much for the information and free pattern. Need a quilt for a baby shower. This will be ideal. Thanks again!!

Helen

Your tutorials are a life save. You have such wonderful hints and ideas. Love your site!!! In addition, your quotes are such an inspiration.

I have been teaching myself the art of quilting for the past year. This site is amazing. I just love everything about it. I love seeing your tutorials and having the ability to analyze the blocks against your instructions for as long as I need to. I am one of those, if I can see it, I get it. Thank you for putting your heart into this site.

Thanks! I always finger pressed the edge of the square and the bias edge of the triangle and I think with some fabrics it stretched that bias just a little.

That’s ‘s for the tips. Can,t wait to try it!!

Thanks for the “square in a square“ tutorial. I just started a quilt with this block, and really needed this info!

Thanks for the free pattern and tips for making a square in a square, very much appreciated. I have lots of HST from projects and can use these scraps to make the pattern.

Thank you for the math!!!!

This is a great tutorial. Thank you for sharing!

This tutorial is so timely for me! I am ready to begin a quilt with a square in a square block. Your tips will help me be more satisfied with the result. Thanks!!

Thank you for a quick reminder of the importance of how to do a good square in square.. Please keep up the good work. I so enjoy all your notes and patterns xxx Pat

Thanks for posting this Very informative I love reading your blogs

I’m so glad I found you again… although this is an old post. ?

I’ve been looking for a simple formula to make these any size and yours is clear and easy. Now to make some square in a square blocks! God bless!

thank you so much, great tutorial

Thank you for this lovely pattern.

Thanks so much for the pattern!!🤗 It will be fun to make.

I am very confused with the block size (s) in relation to the triangles. Do you just make the center square. 3/4″ inch larger then your triangles? Not great at math.