Anyone know?
 

I want to add something to the back of my all white quilt for color. I can't figure out how to figure how big to cut my squares for a pinwheel block that measures 9 inches. The all white on white is just boring. I tried to look it up but no luck. Thank you for the help.

I think you cut your squares at 5.5 inches to make 4.5 HST

Thank you I'll try that.

are you planning on adding pinwheels all over the back?
Is it for a label?

If the front of your quilt is mostly white, be very careful adding color to the back since it might show thru the batting. To make a 9" pinwheel, you will need to make four 4.5" finished HST. Need two sets of 5.5" squares. You get two HST per square and you need 4 HST to make a pinwheel so half of 9" is 4.5" Remember, these are finished sizes.