This calculator helped immensly with my re-intro to trad. It saved alot of arrow spine questions, and let me focus on form, knowing that form was affecting the arrow flight/accuracy and not improper spine.
I'd make a cup or two of coffee if using dial up. Once its downloaded its all up to your computer.
One item: if your bow is not in the drop down list, make sure you accurately check all the factors that need input on the calc.
This program can be greatly affected by the garbage IN garbage OUT saying. When properlyused, its great.
Regards,
Brian