The short answer

For most healthy formula-fed babies, the general rule is about 150–180 mL (5–6 fl oz) per kilogram of body weight per day — spread across as many feedings as your baby needs. Newborns feed 8–12 times a day; older babies (4–6 months) usually settle into 5 feedings.

If you don't know your baby's weight, you can use the age-based table below as a starting point. The BabyMilk calculator lets you enter either age, weight, or both for an instant estimate.

Formula amounts by age

The amounts below are typical ranges — every baby is different, and appetite varies day to day.

Age	Per feeding	Feeds/day
0–1 week	30–60 mL (1–2 fl oz)	8–12
1–4 weeks	60–90 mL (2–3 fl oz)	7–8
1–2 months	90–120 mL (3–4 fl oz)	6–7
2–4 months	120–150 mL (4–5 fl oz)	5–6
4–6 months	150–180 mL (5–6 fl oz)	5
6–9 months	180–210 mL (6–7 fl oz)	4
9–12 months	180–240 mL (6–8 fl oz)	3–4

Sources: American Academy of Pediatrics (AAP), NHS, World Health Organization (WHO).

Using weight instead of age

Once you know your baby's weight, the weight-based method is more accurate than the age-based table — especially in the first six months. The formula is simple:

Metric: 150–180 mL × baby's weight in kg = total mL per day
Imperial: ~2.5 fl oz × baby's weight in pounds = total fl oz per day

Divide the daily total by the number of feedings to get the per-bottle amount. The calculator does this automatically.

The 32 fl oz / 960 mL daily ceiling

Healthy babies almost never need more than 960 mL (32 fl oz) of formula per day. If your calculation comes out higher, cap it there and speak with your paediatrician — it may simply mean your baby is ready for solid foods, or that the formula tin's instructions apply.

When your baby is 6 months and older

From around 6 months, solid foods are introduced. As your baby eats more puréed and soft foods, formula intake naturally decreases. By 9–12 months, most of the daily calorie intake comes from solids, and formula drops to 3–4 bottles a day. At 12 months, most babies transition from formula to whole cow's milk or a suitable plant-based alternative.

Signs your baby is getting enough

Gaining weight steadily (your paediatrician tracks this at check-ups)
6 or more wet nappies/diapers per day
Appears content after feeds
Passes soft stools regularly
Alert and active when awake

If you're unsure, always check with your health visitor or paediatrician — they can weigh your baby and confirm everything is on track.

Important reminders

Always follow your formula manufacturer's preparation instructions exactly — the water-to-powder ratio matters.
Never add extra scoops to make formula more concentrated.
Never add extra water to stretch formula further — this dilutes essential nutrients.
Prepared formula should be used within 2 hours at room temperature or within 24 hours refrigerated.