I need to ask few more questions before answering your query. Early consultations can prevent complications. Kindly contact me on whatsapp chat  (84960595 six five) Dr Faisal Zoheb MBBS , MD PAEDIATRICS , PGPN (BOSTON), FELLOWSHIP IN NEONATOLOGY ( Newborn and vaccination specialist )

Greetings Whether increasing formula is safe depends on your baby's hunger cues and overall growth, as every infant's needs are unique. At four months, many babies consume between 120ml and 180ml per feeding, so your proposed increase is within a common range. However, since you are supplementing after breastfeeding, it is important to watch for signs of overfeeding, such as excessive spitting up or rapid weight gain. You should monitor for fullness cues, like turning away from the bottle or slowing down, to ensure he isn't being pressured to finish.

You can give the feeds as much as the baby wants. Feeding is depending on the baby’s eagerness to take. You can always stop if the baby turns away and doesn’t show interest in feeds. No need to force feed him. Usual feeding should not exceed 20-30 minutes per feed.

Feeding is always baby led. If he taking more, you can try to give

Yes for 4months with 6.4kg  you can give 120ml also

Yes, increasing to 120 mL per feed can be okay if baby still appears hungry after feeds and is tolerating feeds well. Based on current weight (6.4 kg), growth appears appropriate. Increase gradually and observe for vomiting, excessive spit-up, abdominal bloating or discomfort. Continue breastfeeding first, then give top-up only if needed.

Give feed