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Baby feeding amount calculator
How much milk does my baby need per day?
From about one week to six months old, formula-fed babies take roughly 150 to 200 ml of formula per kilogram of body weight per day, spread across all feeds. A 4 kg baby therefore lands near 600 to 800 ml a day, often across 6 to 8 feeds. Breastfed babies are not measured this way — they self-regulate, and wet nappies plus steady weight gain are the signs to watch instead.
Estimate a daily formula amount
For formula-fed babies from about one week to six months old.
Across a whole day
600 – 800 ml
about 20.3 – 27.1 fl oz
Across 6 feeds, that is roughly
100 – 135 ml per feed
about 3.4 – 4.6 fl oz
Based on 150–200 ml per kilogram of body weight per day. If you are breastfeeding, this calculator does not apply — breastfed babies self-regulate, and wet nappies plus steady weight gain are the signs to watch instead. Babies also feed unevenly across a day, so the per-feed figure is an average, not a quota for every bottle.
Baby feeding chart by age
| Age | Per feed | Feeds a day | Notes |
|---|---|---|---|
| First week | ~45–60 ml | 8–12 | Volumes climb steeply day by day as your milk supply establishes. |
| 1 month | ~80–150 ml | 6–8 | A ~4 kg baby lands near 600–800 ml a day in total. |
| 2–4 months | ~120–180 ml | 5–6 | Feeds get bigger and less frequent as the stomach grows. |
| 4–6 months | ~180–240 ml | 4–5 | Most babies plateau near 900 ml a day and stay there. |
| 6–12 months | ~180–240 ml | 3–4 | Milk stays the main nutrition source as solids are introduced alongside. |
The maths behind the estimate
From about one week to six months old, published guidance puts a formula-fed baby's daily intake at roughly 150–200millilitres per kilogram of body weight. Multiply your baby's weight in kilograms by those two numbers and you have the range for a whole day; divide by the number of feeds and you have a rough per-feed figure.
The reason it is a range and not a number is that appetite varies as much between babies as it does between adults. A baby at the bottom of the range who is gaining weight steadily and producing plenty of wet nappies is doing fine.
Why the per-feed number is an average, not a quota
Babies do not distribute their intake evenly. A big morning bottle followed by a small afternoon one is completely normal, and cluster feeding in the evening is common. What matters is the total across the day and the week, not any single bottle.
Forcing a baby to finish a calculated amount works against the appetite regulation they are born with. Paced bottle feeding — letting the baby stop when they show they are done — is the approach most health services recommend.
Feeding questions parents ask
- How much formula does a newborn need?
- In the first week, newborns typically take around 45–60 ml per feed, 8–12 times a day, with volumes climbing steeply day by day. After the first week, the 150–200 ml per kilogram per day guide applies: a 3.5 kg baby lands near 525–700 ml across a whole day.
- How do I know my breastfed baby is getting enough?
- Breastfed babies cannot be measured in millilitres, and trying to is a common source of unnecessary worry. The signs to watch are five or more heavy wet nappies a day from day five, steady weight gain, pale and near-odourless wee, and a baby who is alert and settled after most feeds. If any of those are missing, contact your child health nurse, midwife or a lactation consultant.
- Should I wake my baby for a feed?
- Newborns are usually fed on demand, but babies who have not regained their birth weight, who were born preterm, or who are jaundiced may need waking for feeds. Follow the advice of your midwife, child health nurse or GP over any general guidance, as this is one of the areas where individual circumstances matter most.
- Does my baby need more milk at every feed as they grow?
- Daily intake climbs through the first four to six months and then plateaus, usually near 900 ml a day, staying roughly flat until solids are established. Feeds get larger and less frequent rather than simply more numerous. A baby who suddenly wants much more or much less than usual for more than a day or two is worth mentioning to your health professional.
Where these numbers come from
- NHS Start for Life — Formula volumes per kilogram of body weight in the first six months.
- HealthyChildren.org (American Academy of Pediatrics) — Amount and schedule of formula feedings by age.
- Australian Breastfeeding Association — Expected feeds and nappies through the first week.
Stop doing this maths in your head
BubSync adds up feeds as you log them, so the daily total is already there when you want it — and whoever gives the next bottle can see what the baby has already had, without a text message.