Hi Sue,
I have a box of Cook and Serve Vanilla Pudding in front of me, it weighs 3 oz and requires 2 cups of milk. I also have a box of Sugar-Free Chocolate Pudding which weighs 1.4 oz and requires 2 cups of milk. I don't have any regular instant pudding, so I can't help you there. I am guessing it would be close to the cook and serve pudding ratios. Good luck!