I use Aptimil on the side of the box it says:
3-4 months 5 X 6ozs
4-5 months 5 X 7ozs
These are just guidelines and will depend if you have a hungry baby etc. My HV advised me to put in an extra ounce in the bottle so if babe was hungry she could guzzle it , if not it got chucked - this was good advice as every mealtime is different - better to offer more - you won't overfeed as babes just refuse or posset it back up anyway. HTH