The way I have always done it was 1 part kitten powder to two parts water, so it doesn't matter what each 'part' is. So 15mls powder to 30mls water, etc. It is the amount that they eat that changes as they get older. At 1 week old they should be eating 8mls per oz (28grams) of weight per day divided by the feedings. A 2 oz (56 gram) baby should get approx. 16mls a day divided by 7 feedings would be a little over 2mls for each feeding. A 4oz (112gram) baby should get 32mls a day divided by 7 feedings is almost 5mls per feeding. Of course, if they want a little more give it to them. Try not to feed over 10mls at one feeding until they are a lot older, it may give them diarrhea. Make sure you feed them tummy down like they are nursing on mom, and gently hold them to your shoulder after eating and rub their backs to burp them. They also will need a warm wet washcloth rubbed in circular motions on their genitalia to stimulate them to pee/poop. Please keep us informed how you are doing!