OneTaskBy Tim King · Updated
Baby Formula Calculator
How Much Formula Does My Baby Need?
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How the Baby Formula Calculator works
This baby formula calculator estimates how much formula milk your baby needs each day and at each feed from their weight and age. It gives the amount in millilitres and fluid ounces with a typical number of feeds a day for their age.
How the baby formula calculator works
Most formula-fed babies take about 150 to 200 mL of milk per kilogram of body weight each day in the first six months. The calculator uses a midpoint of 165 mL/kg. The formula is daily amount = weight in kg × 165 mL, capped at about 960 mL (32 fl oz), the usual upper limit. That total is then split by the typical number of feeds for the baby's age, from about 8 a day for newborns to 4 or 5 by six months.
First example. A 5 kg baby at 8 weeks needs about 825 mL (27.9 fl oz) a day, or 6 feeds of about 138 mL (4.6 fl oz).
Second example. An 8 lb newborn at 2 weeks needs about 599 mL (20.2 fl oz) a day, split into 8 feeds of about 75 mL (2.5 fl oz).
How many feeds a day does a baby need? Around 8 to 12 in the first weeks, falling to 6 or 7 by two months and 4 to 5 by six months as each feed gets bigger.
Babies are good at regulating their own intake, so follow hunger and fullness cues rather than forcing the last of a bottle. From about 6 months, solid food gradually replaces some milk.
Daily formula by baby weight at 165 mL per kg (2.5 fl oz per lb), capped at 960 mL, with 6 feeds a day
| Baby weight | Formula per day | Range 150 to 200 mL/kg | Per feed (6 feeds) |
|---|---|---|---|
| 2.5 kg (5.5 lb) | 413 mL (13.9 fl oz) | 375 mL to 500 mL | 69 mL (2.3 fl oz) |
| 3 kg (6.6 lb) | 495 mL (16.7 fl oz) | 450 mL to 600 mL | 83 mL (2.8 fl oz) |
| 3.5 kg (7.7 lb) | 578 mL (19.5 fl oz) | 525 mL to 700 mL | 96 mL (3.3 fl oz) |
| 4 kg (8.8 lb) | 660 mL (22.3 fl oz) | 600 mL to 800 mL | 110 mL (3.7 fl oz) |
| 4.5 kg (9.9 lb) | 743 mL (25.1 fl oz) | 675 mL to 900 mL | 124 mL (4.2 fl oz) |
| 5 kg (11.0 lb) | 825 mL (27.9 fl oz) | 750 mL to 960 mL | 138 mL (4.6 fl oz) |
| 5.5 kg (12.1 lb) | 908 mL (30.7 fl oz) | 825 mL to 960 mL | 151 mL (5.1 fl oz) |
| 6 kg (13.2 lb) | 960 mL (32.5 fl oz) | 900 mL to 960 mL | 160 mL (5.4 fl oz) |
| 6.5 kg (14.3 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 7 kg (15.4 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 7.5 kg (16.5 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 8 kg (17.6 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 8.5 kg (18.7 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 9 kg (19.8 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 9.5 kg (20.9 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 10 kg (22.0 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 10.5 kg (23.1 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 11 kg (24.3 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 11.5 kg (25.4 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 12 kg (26.5 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
| 12.5 kg (27.6 lb) | 960 mL (32.5 fl oz) | 960 mL to 960 mL | 160 mL (5.4 fl oz) |
FAQ
How much formula does a newborn need?
In the first few days only 30 to 60 mL per feed, rising quickly. By the end of the first week most newborns take about 150 mL per kilogram a day, spread over 8 or more feeds.
What is the most formula a baby should have?
Most guidelines suggest no more than about 960 mL (32 fl oz) a day. Babies regularly wanting more than that may be ready for more filling feeds or solids, so check with your health visitor or doctor.
How do I know if my baby is getting enough?
Six or more wet nappies a day, steady weight gain along their growth curve and a contented baby after most feeds are good signs. Speak to a health professional if you are worried about weight gain.
Should I use my baby's weight or age?
Weight is a better guide, since babies of the same age vary a lot in size. Age helps decide how many feeds to split the total into, which is why the calculator asks for both.
Does this apply to breastfed babies?
Not directly. Breastfed babies regulate their intake at the breast and it cannot be measured in the same way. For expressed breast milk in a bottle, these amounts are a reasonable starting guide.
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