I made this set because I am always trying to design something new and without physically seeing the thickness in hand its difficult for me to figure out the best thickness for something that doesn't exist yet.  I made a little box that fits each card to keep things neat on your desk.  
Each card has the inner and outer radius of the same marked mm on the card on the top left and right.

These will not be 100% accurate based on your printer and settings but will help guide you to making a choice on wall thickness for a design.

Card sizes included in mm:

0.5, 1, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25