The tin is just a suggestion. You can give 120ml and see if baby asks for more, then top up from there. For my 5mth baby, 120ml can last for about 2 hours before the next feeding. Take note of the total milk intake for a day and work from there. My baby takes 120ml 6 times a day. Hope this helps.
My 4m++ boy drink 120-140ml every 3hrs. But i always prepare 130ml for him. Night feeding only 1 time which is est 6-7 feeds per day.