How much formula milk?

Hi mums, FTM here. my LO is 3 months old, she is 5kgs and should be drinking around 750ml formula according to calculation but she only can drink around 600-650, sh e is gaining weight and has enough wet diapers and sleeping 6-8 hours at night. I tried feeding her more (150 ml per feed but she doesn't take more than 120 ml and cries a lot if I try to feed her more Should I be concerned about her intake or is this normal? Should I wake her up at night to feed? Please advice and share your experience