Baby Milk & Formula Calculator
Enter your baby's age and weight and get the daily amount of formula or breast milk they need — plus how much goes in each feed. Built on published AAP and NHS feeding guidance.
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How much milk a baby needs by age
Total daily milk by age, with the number of feeds it's usually split across. Formula and breast milk are listed separately because they follow different patterns: formula tracks body weight in the early months, while breastfed intake plateaus from around one month and stays there.
| Age | Formula per day | Breast milk per day | Feeds per day |
|---|---|---|---|
| 0–1 mo | 14–22 oz (420–650 ml) | 14–22 oz (420–650 ml) | 8–12 |
| 1–2 mo | 19–27 oz (560–800 ml) | 19–30 oz (570–900 ml) | 7–9 |
| 2–3 mo | 22–30 oz (650–890 ml) | 19–30 oz (570–900 ml) | 6–8 |
| 3–4 mo | 23–31 oz (680–920 ml) | 19–30 oz (570–900 ml) | 5–7 |
| 4–5 mo | 24–32 oz (710–950 ml) | 19–30 oz (570–900 ml) | 5–6 |
| 5–6 mo | 24–32 oz (710–950 ml) | 19–30 oz (570–900 ml) | 5–6 |
| 6–9 mo | 21–27 oz (620–800 ml) | 19–27 oz (570–800 ml) | 4–5 |
| 9–12 mo | 17–24 oz (500–710 ml) | 16–24 oz (470–710 ml) | 3–4 |
| 12–18 mo | 14–20 oz (410–590 ml) | 12–20 oz (350–590 ml) | 2–3 |
| 19–24 mo | 14–20 oz (410–590 ml) | 10–18 oz (300–530 ml) | 2–3 |
Ranges reconcile guidance from the American Academy of Pediatrics (about 2.5 fl oz per pound per day, to a ceiling of 32 fl oz) with the NHS figure of 150–200 ml per kg per day, and with measured intake data for exclusively breastfed babies. Guidance for over-ones diverges internationally — the AAP suggests 16–24 fl oz of whole milk a day while the NHS suggests nearer 300–400 ml — so the toddler rows span both. Healthy babies vary widely; treat every figure here as a starting point, not a target to hit.
How much formula by weight
The rule most paediatricians use for formula-fed babies under six months: about 2.5 fluid ounces per pound of body weight per day, or 150–200 ml per kilogram. Find your baby's weight to read off the day's total.
| Weight | Typical per day | Reasonable range |
|---|---|---|
| 6.0 lb (2.7 kg) | 15 oz (440 ml) | 13–17 oz (390–500 ml) |
| 8.0 lb (3.6 kg) | 20 oz (590 ml) | 18–23 oz (530–670 ml) |
| 10.0 lb (4.5 kg) | 25 oz (740 ml) | 22–28 oz (660–840 ml) |
| 12.0 lb (5.4 kg) | 30 oz (890 ml) | 27–32 oz (790–950 ml) |
| 14.0 lb (6.4 kg) | 32 oz (950 ml) | At the daily maximum |
| 16.0 lb (7.3 kg) | 32 oz (950 ml) | At the daily maximum |
| 18.0 lb (8.2 kg) | 32 oz (950 ml) | At the daily maximum |
| 20.0 lb (9.1 kg) | 32 oz (950 ml) | At the daily maximum |
Applies to formula-fed babies under six months. After six months solids take over and the weight rule no longer holds. No formula-fed baby needs more than 32 fl oz (950 ml) a day.
Common questions
How much formula should my baby have per day?
For babies under six months, the American Academy of Pediatrics rule of thumb is about 2.5 fluid ounces of formula per pound of body weight per day — roughly 150–200 ml per kilogram, the figure the NHS uses. A 10 lb (4.5 kg) baby therefore lands around 25 fl oz (740 ml) a day. No formula-fed baby needs more than 32 fl oz (950 ml) a day. After six months, solids take over and the weight rule stops applying: intake eases to roughly 21–27 fl oz (620–800 ml) at 6–8 months and 17–24 fl oz (500–710 ml) at 9–11 months.
How many ounces of formula for a 12 pound baby?
About 30 fl oz (890 ml) a day, using the 2.5 fl oz per pound rule, with a reasonable range of roughly 27–31 fl oz (790–920 ml). Split across five feeds that is about 6 fl oz each; across seven feeds, about 4.5 fl oz. A 12 lb baby is typically three to four months old, and this figure assumes they have not yet started solids.
How much breast milk does a baby need?
Exclusively breastfed babies take a remarkably steady 19–30 fl oz (570–900 ml) a day from about one month through to six months, with an average close to 25 fl oz (750 ml). Unlike formula, this does not scale up with weight: as a baby grows, breast milk becomes more calorie-dense rather than more plentiful. That is why a six-month-old and a two-month-old often drink almost the same volume.
How do I know my baby is getting enough milk?
Nappies and the growth chart, not the bottle. From about a week old, expect six or more heavy wet nappies a day with pale, almost odourless urine, and steady weight gain along your baby's own centile line. A baby getting enough is usually settled and alert between feeds and comes off the bottle or breast of their own accord. Fewer than six wet nappies a day, dark strong-smelling urine, dropping across centiles, or a baby too sleepy to wake for feeds are all reasons to contact your health visitor or doctor.
Should I wake my baby to feed?
In the first few weeks, usually yes — most guidance says not to let a newborn go more than four hours without a feed until they are back above birth weight and gaining steadily. After that, a healthy baby who is growing well can be left to wake on their own overnight. If your baby is consistently sleepy and hard to rouse for feeds at any age, that is worth a call rather than a wait.
Does my baby need less milk once they start solids?
Eventually, but not straight away. For the first few weeks of solids, food is practice — texture, skills and iron — and milk stays the main source of nutrition. The daily total typically eases from around 24–32 fl oz before six months to 21–27 fl oz at 6–8 months and 17–24 fl oz at 9–11 months, as meals go from one a day to three. If milk drops away much faster than that, offering it before solids rather than after usually slows it down.
Keep exploring
This calculator gives general guidance based on published feeding recommendations from the American Academy of Pediatrics and the NHS. It is not medical advice, and it cannot account for prematurity, reflux, allergies, faltering growth or any other individual factor. Healthy babies vary enormously — feed on demand and follow your baby's hunger and fullness cues rather than a number on a screen. If you have any concern about your baby's feeding, weight gain or wet nappies, speak to your health visitor, midwife or paediatrician.
Last updated: August 2026
