Bias Tape Calculator
Enter your fabric square size and strip width to see how much bias tape you can cut.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
Can't find what you need?
Request a ToolHow to Use the Bias Tape Calculator
Bias tape is cut on the 45-degree diagonal of the fabric, which gives it stretch and allows it to curve around edges smoothly. The continuous bias method lets you cut an entire square of fabric into one long, unbroken strip. This calculator tells you how much tape you will get.
- Enter your fabric square size. This is the side length of the fabric square in inches. An 18"×18" square of quilting cotton is a common starting point. Larger squares yield much more tape since the yield scales with the square of the fabric size.
- Enter the strip width. This is how wide each bias strip will be before folding. For single-fold bias tape finished at 1/2", cut strips 1" wide. For double-fold tape finished at 1/2", cut strips 2" wide. For quilt binding, 2 to 2.5" strips are standard.
- Read your yield. The calculator shows total yards and approximate number of strips. Use this to decide how large a fabric square to cut from your yardage.
About the Bias Tape Calculator
The formula for continuous bias tape yield is: total length (inches) = fabricSize² / stripWidth. This comes from the fact that the total area of the fabric is fabricSize², and each strip covers an area of (fabricSize × stripWidth) along the diagonal. The actual yield from the continuous bias method (where you sew the fabric into a tube and cut in a spiral) is very close to this theoretical maximum because very little fabric is wasted at the seam. Conventional cut strips (separate diagonal strips sewn end to end) yield slightly less due to the diagonal cut waste at each end.
Frequently Asked Questions
How much bias tape do I need to bind a quilt?
To bind a quilt, measure the perimeter and add 10–12 inches for corners and joining. A twin quilt (68"×90") has a perimeter of 316 inches, or about 9 yards. Buy or make a few extra yards as a buffer. For 2.5" binding strips (the standard), an 18"×18" square of fabric yields about 162 inches (4.5 yards) of bias binding, so you would need two or three 18" squares for a twin quilt binding.
What is the continuous bias tape method?
Cut your fabric into a square. Mark diagonal lines across the fabric at your desired strip width. Bring two opposite sides together with right sides facing, offsetting by one strip width, and sew a seam. This creates a tube. Cut along the marked spiral line to produce one continuous strip. The result is a single long strip with no joins — much cleaner than piecing individual diagonal strips together. This calculator gives you the yield for this method.
How wide should I cut bias strips for double-fold bias tape?
For double-fold bias tape that finishes at 1/2" (the most common size for garment edge finishing), cut strips 2" wide. The bias tape maker folds each edge to the center (consuming 1" total), then folds in half again to create a 1/2" finished tape. For 1/4" double-fold tape (used for quilt bindings and narrow edges), cut strips 1" wide. For 3/4" tape, cut strips 3" wide.
Why cut bias tape on the diagonal instead of straight grain?
The diagonal (bias) of woven fabric has much more stretch than the straight grain. This stretch allows bias tape to curve around rounded edges, necklines, and armholes without puckering. Straight-grain tape would pucker or create tucks when sewn around curves. The diagonal cut also makes bias tape more stable when stretched slightly, since the weave structure distributes the tension evenly. This is why all commercial bias tape is cut on the 45-degree diagonal.