Friday, August 05, 2011

Cutting Bias Bindings!

The other day I got a comment on my Binding Tutorial that read:

“How can you figure out how much binding/yardage you will need for a quilt when you are making BIAS BINDING? I have seen the chart for straight binding, and that's great, but how do you figure out the measurements when you're cutting bias binding??”

Quilts with curved edges require bias binding so the binding fabric will easily move around the curve without cupping and puckering. And sometimes, a stripe or plaid look BETTER cut on the bias than on the straight for the effect that you want. I’ve also been told that bias binding doesn’t wear out as quickly because the straight of grain is not on the edge of the quilt. It’s stronger.

((This pic is the BACK side of a quilt that is being released in a German magazine coming up, I can't show the front yet!))

This is MY take on the situation and how I choose to work with things, even though there may be other ways, other methods, other books, other tutorials, other charts for cutting squares etc. on the subject. This is just me sharing me....and a bit of why I do what I do and why it works for me.

The challenge with cutting bias binding comes in the calculation -----Usually a square is cut from the fabric, the square cut on the diagonal, and the pieces rotated and joined back together into a parallelogram. Lines are drawn, pieces are offset, and re-sewn into a tube, and then the tube is cut on the line with scissors.

The problem with this is that if you are "offsetting" your lines, aligning the top line with the line 2” below it --- your bias binding is not really on the “TRUE” bias. And you have to cut all that bias by hand with scissors after your tube is sewn together. To me the process is awkward.

And sometimes it doesn’t WORK for me to cut a big honking square of fabric! What if I want to bind a quilt that says that I need a 29” x 29” square? And I only have 1/2 a yard that measures 18” X 42”? Can’t I make better use of the fabric that way?

First off, you need to know the perimeter measurement of your quilt. Side + Side + Top + Bottom. And just to be safe, I add another 12” to that measurement. I need to figure the excess I need to miter corners and join the binding ends within that measurement.

And it also helps to think of standard quilt sizes when planning binding. That way I can figure out in my head based on the following what I’ll need:

Inches required for STRAIGHT EDGED QUILTS ((Curved and scalloped edge quilts will require more, plan accordingly))

Twin: 68” X 90”. Perimeter measurement + additional 12” = 328” 0f binding needed.

Double: 80” X 90”. Perimeter measurement + additional 12” = 352” of binding needed.

Queen: 90” X 108”. Perimeter measurement + additional 12” = 408” of binding needed.

King: 110” X 110”. Perimeter measurement + additional 12” = 452” of binding needed.

So these are my ball park figures that help me decide what size of fabric yardage to start with.

The more narrow the bias binding, the easier it hugs the curves and the better it looks in my opinion, so I tend to cut my bias at 2” for a binding that finishes at a snug 1/4”. I know some people like 3/8” binding and want to cut it at 2 1/4”. Just do a small recalculation using the following formula and it should work for you!

So here we go! Are you ready? ((Click HERE for Printer Friendly Version!))

1.) Measure the perimeter of your quilt and add 12". Divide this number by 42 (assuming about 42" of usable width on 44/45" wide yardage) and round up to the next even number.

2.) Multiply this number by your desired cut strip width . This final number is the length of the rectangle needed to make your continuous bias binding strip.

For example:

  • Quilt measures 71" x 90"
  • Perimeter = 71+90+71+90 = 322 and add 12" for a total of 334"
  • 334 divided by 42 = 7.95 Round this up to 8
  • 8 x 2 (for 2” binding strip width) = 16
  • You'll need a 16" x 42" piece of fabric for the binding

So I can get that bias binding out of a 1/2 yard of fabric instead of having to cut a 29” square!! That’s a much better use of the fabric, don’t you think?

You can use your own measurements in the formula above for figuring out your OWN needed size! Try it, it’s easy!


This is my drawn piece of yardage!

cottoncandy 018

This is my actual piece of yardage! Fold one end of the rectangle over and align the edge like this:


I leave the fabric folded, and use my scissors to cut along the fold like this:

cottoncandy 019

This is my TRUE bias. You can see I’ve placed a couple of pins away from the fold to keep things from shifting as I cut….And yes, there is a piece of green fabric tied to my scissors to warn any family members that these are FABRIC SCISSORS ONLY!


Move the cut off triangle to the other end of the rectangle, and sew the selvage edges together. Press this seam open.

Here it is on MY fabric:

cottoncandy 020

Yes, I was making LOTS of purple bias binding! I was binding scallops, so I had to calculate in extra length. This is a fairly LARGE cut of fabric for that reason, but the method is the same!


At this point, to keep the true bias, I just cut strips the width that I need from the bias edge of the parallelogram. You CAN do the drawing all the lines 2” apart, and sew the whole thing into a tube by offsetting it one line, and then cut with scissors on the lines to have it all in one length, but remember….it’s just “THAT MUCH” off the true bias if you do. And I find that the ability to fold the piece, use my rotary cutter to quickly cut strips, and seam them end to end is actually a faster process for me.

If you want to view the “tube” method with squares, go HERE.

cottoncandy 021

My 12.5” ruler isn’t long enough…I like this 14” one with it’s easy to read big numbers!

cottoncandy 022

When joining the strips end to end, be sure to overlap and leave dog ears at each end. Your stitching should come out right at the “V” in between the two pieces of fabric. Press seams open!

Applying the binding to straight edges is the same as with straight cut binding. You can visit my Binding Hints page to see how I apply binding, miter corners, and join ends.

I plan on doing a curved binding tutorial when time allows! I know I’ll need to have one in place when the quilt I have in the German Magazine is released…so be watching for it!


  1. Thanks for that easy formula! So much more professional than *hoping* that bit I have left is going to be enough to get a bias binding. lol Been lucky so far, but nice to go forward with a bit more confidence!

  2. Thanks for posting this tutorial, Bonnie. When making bias binding~I prefer to cut and sew like you rather than the *tube* method

  3. Thanks for the great tutorial. I've never tried bias binding, and I can guarantee I wouldn't like the tube method. I'm glad to know your formula and method. Now to just find some great fabric and give it a try!

  4. I love how you make PDF's for us. I am actually on my third binder holding all your patterns. The mysteries have their own PINK binder.
    I just bought the Easy Angle Scallop tool. I have a feeling we are going to need it in the future!
    XOXOXO Subee

  5. This is just the way I do it to, but have always just measured the quilt I am binding, then "ballpark" the binding length by adding a bit more. Thanks for the real charts of proper lengths :0).
    Don't you love the way Subee thinks? I think she missed her true calling of being a world famous home organizer. I wish I could get my brain to "see" like hers!

    I'm getting excited to add the binding to my two RRCBs to give as Christmas gifts. thanks again Bonnie for another terrific mystery. Do you have one "cooking" for this holiday season?

    Welcome home and Happy Sewing

  6. I always, always use bias binding and feel it makes for a much nicer edge. It wears better too. I measure the quilt perimeter, figure how long each bias strip is and just do the math. I love my wide acrylic yardstick!! As for the tube method of bias strip making--it's always seemed like re-inventing the wheel to me. It's simple enough to just cut strips and seam them together.

  7. This is fine for straight edged quilts, but you must add more if the edges are curved! You pics are great. one more reason to NOT use the big old square method is the number of seams you end up is far more than the rectangle version! (and i hate trying to cut it all by hand.)

  8. Thank you so much for this post...the information is perfect and very useful! This is the way I've made binding, but I never knew how to figure how much fabric I needed...and I always thought this wasn't the "proper" way to make it. So yay, I was doing it an acceptable way. :)

  9. I have ordered a bias ruler. The video looked good, but mine hasn't arrived yet. Might be worth looking at?

  10. I like to sew the binding sections together as I sew the binding to the quilt so that I can control where the join will fall. It is really frustrating to find that join at the very place you are trying to make a neat mitered corner.

  11. Thanks for this - I stopped making bias binding because that tube method was so cumbersome, but this I will try!

  12. cathryn matthews7:12 PM EDT

    I just happened across your bias tutorial, and was confused to see the last photo. I believe it is an error in your tutorial, as you are showing how to join the strips end to end, but that last photo shows you joining the bias edge to the straight edge of the other strip. Correct me if I'm wrong, but... that wouldn't work!?

  13. I have been looking for a GOOD bias tutorial and have stumbled across yours by mistake!! It is great and the site is now on my favourites bar. I am a lapsed quilter but......methinks no longer!!!!!! BTW - I am in the UK

  14. Anonymous10:20 PM EDT

    Thank you for the tutorial. The one thing I haven't found addressed anywhere is how to account for/ calculate the extra length needed for scalloped edges. All of the instructions I've found say to allow extra for scalloped edges, but not how to estimate how much extra. Any help would be greatly appreciated!

  15. I just love this method of making bias binding. I "did the tube thing" for 30 years (!) and never liked it. Now I'm a happy quilter thanks to you.


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