Formula Fed

I’m facing exactly the same issue as you. My baby is almost 2 months, weighs 4.8kg and I’m feeding him 90ml formula per feed. When it comes to the last 20ml, he will usually gag and use his tongue to push the teat. I try to force him to finish the last 20ml but the milk will just accumulate in his mouth as he won’t swallow. If I did force him, he would sometimes vomit all the milk. So I usually won’t force him and take it as his capacity is 70ml, although there are occasions where he could finish all 90ml. When he was just born, a PD told me that to know the amount of formula milk per feed, we can multiply baby’s weight by 20. You can also read the info in the attached photo. For the first four months, we can multiply baby’s weight by 15 to 20 for the amount of formula per feed. How old is your baby and the weight? Also, to take note of the flow of the teat. If it’s too slow for baby, he might get tired to sucking by the time the milk is left with 20ml in the bottle.