Quilt-Pro does the same thing.

Joanns sells a quilt calculator. I've used mine all the time. It comes with a wonderful instructional DVD. With the 50% off coupon I got mine for under $20

Thanks for posting this -- while figuring it out by myself works ok, it's nice to have a way to check that I'm on with the numbers. One thing about our QB -- it always gives us new tools to use and increases our knowledge about quilting.

Thank you fo posting this link! It's going to be a great help!

I use the Robert Kauffman Quilt calculator app on my iPad, but you can also use it on a computer (http://www.quiltersparadiseesc.com/Calculators.php). I have made three quilts using this calculator, and all measurements have been totally accurate with just enough leftover fabric in case of mistakes.