never had the spine calculator work myself. just went to the old trial and error method.
I use 400 spine GT velocities. cut to 30.5" 300gr points, 14gr inserts, arrow wrap and 3x4" feathers. running 586gr with near 29% foc. if I went to 500 velocities cut to 29.5 I was pushing 32% foc. I like to draw 29" so that was a bit to close to my fingers for my taste.