Some times there is a line of stitching dividing the tube in half into two closed tubes. I left mine an open tube. One side holds the yoga mat, the other side becomes the handle. Here is the bag untied.
Here I am using it as a yoga mat tie to keep the yoga mat rolled up. It makes putting the mat into the bag a much easier operation. (Yoga mat tie is 34″ long and 2″ wide before stretching and knotting.)
My finished dimensions were 17″ around x 83″ long. I think it could be slightly wider and 12″ longer. Make sure to add seam allowances and hem allowances if you make your own. This is my first one and it went to the friend who donated her sari for me to sew with. It was for her son, so I didn’t use the pretty part with all the embroidery, but I will make another from that section of sari soon.