Nice quilt.
If you use a full jelly roll there are 42 strips. The finished quilt ends up being approximately 50" x 64".
I have mad the calculations for using 20 or 24 strips. When you get down to around 120", you cut it into three equal pieces and end up with a baby or lap size quilt of around 48" x 30" I think.
Here is a link to the one I just finished up and added borders to.
http://madewithlovebymary.blogspot.c...up-friday.html