How do I calculate how much fabric I need for my binding?

Here are the steps to calculating how much fabric you need for the binding of your quilt.  Simply replace the initial size with the measurements from your quilt!

To calculate the amount of binding fabric you need for a 40" square quilt, you can follow these steps:

1. Calculate the Perimeter of the Quilt:

Since the quilt is square, each side is 40 inches.  Here you should use your quilt's measurements.

{Perimeter} = 4 x 40 = 160"

2. Add Extra Length for Corners and Joining:

It's a good idea to add some extra length to account for mitered corners and joining the binding ends. Adding about 10 inches should suffice.

{Total Length Needed} = 160 + 10 = 170"

3. Determine the Width of the Binding Strips:

The width of the binding strips can vary. A common width for quilt binding is 2.5 inches. If you prefer a different width, adjust accordingly.

4. Calculate the Number of Binding Strips Needed:

To find out how many strips you need, divide the total length by the width of the fabric. Most quilting fabrics are 42-44 inches wide. Using 42 inches for calculation:


Since you can't have a fraction of a strip, you'll need 5 strips.

5. Calculate the Total Fabric Required:

Multiply the number of strips by the width of each strip to find the total amount of fabric needed.

{Total Fabric Needed} = 5×2.5 inches = 12.5 inches

Convert inches to yards (since fabric is typically sold by the yard):



You need approximately 0.35 yards of fabric for the binding of a 40" square quilt, assuming you use 2.5-inch wide strips. To be safe, you might want to purchase 0.5 yards to ensure you have enough fabric to work with.