I gave my girl about 60ml -2hrs apart when she was 6weeks old. If you are worry about your LO not having enough, you can slowly increase the volume. I don't calculate or fed my girl according to her weight. I started with 30ml when she was a NB, slowly increase to 60ml when she cries for more. Whatever left over, I will just discard.
60 - 80 ml every two hours .. mix accordingly stated on the tin , if ur lo poo too tight or hard mix more water fm