6.5" because its going to be a block for a charity quilt. There is a cat rescue that has a live webcam and I love to watch the kitties. One of the members came up with the idea of making a friendship quilt and auctioning it to raise funds for the center. This is the block size that the quilter wants us to use. The cat pictured is one of my favorites and I would like to make a block from his picture. I have given thought to doing a more traditional cat quilt block and then maybe doing a larger one from this cat as a wall hanging for another fundraiser that they have later on in the year but really would love to have him on the first quilt!!