Should Follow Formula Tin Recommendations Or PD?

New daddy here.. PD advised wk 1 newborn 50-60ml, then subsequent week increment of 10ml each. So by week 4 we feeding 100ml now. But the tin indicates wk 3/4 120ml.. Should we follow PD or the formulation recommendations? Diaper count and poo healthy still even when you following PD, but we don't want to over or under feed our LO... Any advice?