I would like to thank Julie (justjulier on SCS) for making up this very cool Dynamic Cutting Calculator Excel spreadsheet! Click on the very first post and there is an attachment.
This handy little calculator lets you enter in the size of the layers of your cardstock and it will tell you how many you can fit on one sheet. You can also tell the spreadsheet how many projects you want to make and it will tell you how many sheets of cardstock you need, as well. This is awesome for when you're making a ton of cards or projects!