Baby drinks small amounts

600 ml at that age is, I think, really the minimum—it's quite little. Maybe the bottle takes too much effort to drink from? Try a different bottle/nipple or switch to another type of formula, because sometimes they just don't like certain formulas.

My 6-month-old daughter still drinks 5 bottles of 150ml each. I can't get her to drink any more.

My little boy is 7 weeks old now and has this too. His amounts used to go up to 200 cc! 7 times a day. But now he's having a setback, that's my impression. I really have to force him to drink and then he only drinks about 130. And I have to give him another 40 or so two hours later. No idea how this happens.

You should base it on about 150cc of formula per kilo of body weight.
Lucas weighs, for example, 5000 grams and can then have 5x150cc + 750cc.

Haha, poor guy, he can have more than what he's getting, I see now (clever) but okay, plenty of fat so we'll do it slowly.

That 1000 cc per day was indeed always the case, but now I was told that's no longer true by the CB...

Now I give our third Hummel 10 drops of vitamin D per day, whereas with the previous two it was from age one when they started drinking regular milk, up to age four... also changed again ;-)

It's weight x 150 divided by the number of feeds...

Our little guy is almost 10 weeks old too and now drinks 6 to 7 times 150 cc. I've tried 150/5, but then he spits up too much, and this works well for now...

I always say, if they don't want to drink anymore, you can't force it down their throats anyway, right? ;-)