Feeding Amount by Age Calculator
Estimate how much milk a baby needs by age — ounces or mL per feeding, feedings a day, total daily milk and hours between feeds — for formula or expressed breast milk, with the AAP weight rule (2.5 oz per pound, up to 32 oz), a sample feeding schedule and a by-age chart.
How it works
Per feed and feeds a day from age bands (AAP / CDC guidance) · Total = per feed × feeds · Interval = 24 ÷ feeds · Weight rule (formula, under 6 months): daily total = 2.5 oz × weight in lb (≈ 163 mL per kg), at most 32 oz (≈ 950 mL) · Expressed breast milk, 1–6 months: about 25 oz (750 mL) a day ÷ feeds · 1 fl oz = 29.6 mL
In the first days babies take tiny feeds — about 1 to 2 oz (30–60 mL) every 2 to 3 hours — then move toward larger, less frequent feeds as their stomach grows: around 3–4 oz by the end of the first month and 6–8 oz by six months. Total daily milk climbs to roughly 24–32 oz by a few months old and then plateaus, because each feed gets bigger while the number of feeds falls. For formula-fed babies under six months the American Academy of Pediatrics also gives a weight rule of about 2.5 oz a day for every pound of body weight, up to an average of 32 oz; choose “Age and weight” to use it. Breastfed babies take a remarkably steady amount between one and six months — on average about 25 oz a day — so for expressed milk the calculator divides that by the number of feeds. Once solids begin near six months, milk stays important but stops being the only source of calories. Amounts can be shown in fluid ounces or millilitres, with a sample schedule from your first feed of the day.
Worked example
At 4 months, plan about 5 oz (150 mL) per feed across 6 feeds — roughly 30 oz of milk a day, or a feed about every 4 hours, starting 06:00, 10:00, 14:00, 18:00, 22:00 and 02:00. By the weight rule, a 14 lb baby needs 2.5 × 14 = 35 oz a day, which is capped at 32 oz, or 5.3 oz over 6 feeds. A 3-month-old on expressed breast milk feeding 8 times a day needs about 25 ÷ 8 ≈ 3.1 oz per bottle.
Sources: HealthyChildren.org (AAP) — Amount and schedule of formula feedings · CDC — How much and how often to feed infant formula · CDC — How much and how often to breastfeed · KellyMom — How much expressed milk will my baby need?
Frequently asked questions
How many ounces should a baby eat by age?
Rough guide: the first week 1–2 oz per feed, by one month 3–4 oz, 2–4 months 4–6 oz, and 6–8 oz from about six months. Total daily milk lands near 24–32 oz for most of the first year — follow hunger cues over exact numbers.
How often should I feed a newborn?
Newborns feed roughly 8–12 times a day (every 2–3 hours), including overnight. Feed on demand rather than by the clock, watching for rooting, hand-to-mouth and fussing before crying.
How much formula does a baby need by weight?
The AAP rule of thumb is about 2.5 oz of formula a day for each pound of body weight, up to an average of 32 oz in 24 hours. A 12 lb baby needs about 30 oz a day — 5 oz over 6 feeds. The rule applies to babies on formula only, before solids.
How much expressed breast milk should I put in a bottle?
Between one and six months breastfed babies take about 25 oz (750 mL) a day on average, within a range of 19–30 oz. Divide by the number of feeds: with 8 feeds a day, about 3 oz per bottle. Breast milk intake does not keep rising the way formula does.
Does this apply to breastfed babies?
Babies feeding at the breast self-regulate, so you rarely need to count ounces. Use the frequency as a guide, and choose “Expressed breast milk” when you are filling bottles for a caregiver.
When should I worry my baby is not getting enough?
Call your pediatrician if your baby has fewer than six wet diapers a day after the first week, is not regaining birth weight by about two weeks, seems very sleepy and hard to wake for feeds, or regularly wants much more or less than these ranges.
Related calculators
Typical planning estimate — every child differs. Follow your pediatrician for feeding and sleep decisions.