Measuring fabric for continuous binding.
Add up the total inches around the quilt, divide that by 40 (the standard width of the fabric), round that number up to a whole number and multiply that by the width you cut your bindings.
If your quilt measures 46" X 46"
46 x 4 = 184
divide by 40 =4.6
Round up to 5, you will need 5 strips for the binding. Now if you cut your bindings 2.5 inches, you will need 12.5 inches. So 1/2 yard would be more than enough.