How many ml's of formula milk should my baby of 1 month and a week drink and how often?

Feeding baby: If the baby is held or seated, and there is an adult holding the bottle, the baby should be allowed to drink as much as s/he likes, usually 90-120cc, adjustable depending on weight. The baby indicates need to feed again, which could be every 3 hours, more or less. Sometimes baby will take more at a feeding and less at another. Let baby adjust, and check baby's weight with pediatrician.

720-900ml daily: A 5 week old should be drinking 720-900 ml daily. How much per feeding is a bit more difficult to answer. If it's been awhile since last feeding, a 5 week. old could take as much as 120ml a feed. If baby just had a big feeding 2 hours ago, may only take 60ml at that feeding. Just like adults don't eat exactly same amount each time we eat, neither do infants. Keep track for 24-48 hours,see if okay.