How much formula? Here’s what the guidelines say.
The American Academy of Pediatrics and some NHS trusts each publish a rule of thumb for how much formula a baby takes in a day, based on weight. Enter your baby’s weight and you’ll see what each one gives, in their own words, with a link. No account, and nothing you type gets sent anywhere.
Enter a weight
| Guideline | Per 24 hours |
|---|---|
| American Academy of PediatricsFormula-fed babies. Capped at their stated 32 oz a day. | About 2½ fl oz (75 ml) for every pound (453 g) of body weight |
| NHS Nottinghamshire HealthcareFormula-fed babies, after the first week, to around 6 months. | 150–200 ml for every kg of body weight |
Where these numbers come from
American Academy of Pediatrics (United States)
On average, your baby should take in about 2½ ounces (75 mL) of infant formula a day for every pound (453 g) of body weight… Your baby should usually drink no more than an average of about 32 ounces (960 mL) of formula in 24 hours.
NHS Nottinghamshire Healthcare (United Kingdom)
After your baby's first week, as a rough guide, they'll be taking 150-200ml per kg of their weight per day until they're around the age of 6 months.
NHS (United Kingdom), which doesn’t give a number
All babies are different. Your baby will know how much milk they need.
The per-kilogram figure comes from an NHS trust, not nhs.uk, so it carries the trust’s name.
The two rules land close together. The AAP’s works out at around 165 ml per kilogram a day, inside the trust’s range of 150 to 200.
When these numbers don’t apply
- Breastfed babies. Neither guideline is about them. A breastfed baby feeds to appetite, and nobody measures the volume.
- Once solids start, usually around six months. Milk isn’t the whole diet anymore, and both guidelines stop applying.
- The first week. The trust’s figure starts after the first week, and a newborn’s intake climbs fast over those days.
- Premature babies, and any baby under medical care for feeding or growth. The people looking after them work out their intake, from much more than a weight.
By age rather than weight? The baby feeding chart quotes the CDC and the AAP for each age, formula and breastfeeding.
Bottle sizes in milliliters and ounces
Bottle marked in the other unit? A US fluid ounce is 29.57 ml and a UK one is 28.41 ml, so a 240 ml bottle is 8.1 ounces in the US and 8.4 in the UK.
Milliliters to ounces
| Milliliters | US | UK |
|---|---|---|
| 60 ml | 2.0 fl oz | 2.1 fl oz |
| 90 ml | 3.0 fl oz | 3.2 fl oz |
| 120 ml | 4.1 fl oz | 4.2 fl oz |
| 150 ml | 5.1 fl oz | 5.3 fl oz |
| 180 ml | 6.1 fl oz | 6.3 fl oz |
| 240 ml | 8.1 fl oz | 8.4 fl oz |
Ounces to milliliters
| Fluid ounces | US | UK |
|---|---|---|
| 2 fl oz | 59 ml | 57 ml |
| 3 fl oz | 89 ml | 85 ml |
| 4 fl oz | 118 ml | 114 ml |
| 5 fl oz | 148 ml | 142 ml |
| 6 fl oz | 177 ml | 170 ml |
| 8 fl oz | 237 ml | 227 ml |
The calculator above uses US ounces. Ounces round to one decimal, milliliters to the nearest whole one.
Heading to a checkup? Bundle of Joy logs every feed with the amount and who gave it, so you arrive at the appointment with real numbers instead of an estimate.
The other free tools
- WHO growth chart calculator. Plot a weight and get the percentile.
- Baby age calculator. Days, weeks, months and corrected age.
- Baby weight converter. Kilograms to pounds and ounces.
- Diaper size calculator. Which sizes fit a given weight.
When did she last eat?
Bottles, breastfeeds and diapers, shared with your partner.
