About

Incorrect feeding volumes cause the two most common infant problems: underfeeding (failure to thrive, hypoglycemia) and overfeeding (reflux, obesity risk, colic). A newborn's stomach capacity is roughly 7 mL/kg at birth, expanding to approximately 150 mL by 6 months. This calculator uses the weight-based method endorsed by the AAP and WHO: daily intake = W × F, where W is body weight in kg and F is an age-dependent factor ranging from 150 to 200 mL/kg/day for the first 4 months, then tapering as solids are introduced. It cross-references results against the Holliday-Segar fluid maintenance formula for a safety floor.

This tool approximates intake assuming a healthy, term infant with no metabolic conditions. Premature infants, infants with GERD, or those on specialized formulas may require adjusted volumes prescribed by a pediatrician. Results should not replace medical advice. Pro tip: actual intake varies ±15% day-to-day. Track wet diapers (6+ per day after day 4) as the most reliable hydration indicator.

Formulas

The primary calculation uses a weight-based daily intake model. The age-dependent factor F reflects pediatric nutritional guidelines (AAP, WHO) and accounts for the natural reduction in milk dependency as complementary foods are introduced.

D = W × F(age)

where D = total daily intake in mL, W = body weight in kg, and F is the age-dependent intake factor in mL/kg/day.

The factor F is defined as a piecewise function:

F = {

180 - 200 mL/kg/day if age < 7 days150 - 180 mL/kg/day if 1 - 8 weeks140 - 160 mL/kg/day if 2 - 4 months130 - 150 mL/kg/day if 4 - 6 months100 - 130 mL/kg/day if 6 - 9 months80 - 120 mL/kg/day if 9 - 12 months

Per-feed volume is calculated as:

V_feed = Dn

where n = number of feeds per day (derived from age-appropriate feeding frequency). The Holliday-Segar formula provides a safety cross-check for minimum fluid maintenance:

M = 100 × W mL/day for first 10 kg

where M = minimum daily fluid requirement. If the calculated intake D falls below M, the tool flags a warning.

Reference Data

Age Range	Stomach Capacity	Per Feed Volume	Feeds / Day	Daily Intake (approx.)	Notes
Day 1	5 - 7 mL	5 - 7 mL	8 - 12	30 - 80 mL	Colostrum phase
Day 2 - 3	15 - 25 mL	15 - 25 mL	8 - 12	120 - 300 mL	Transitional milk
Day 4 - 7	30 - 60 mL	30 - 60 mL	8 - 10	300 - 600 mL	Mature milk arrives
Week 2 - 4	60 - 90 mL	60 - 90 mL	8 - 10	480 - 720 mL	Cluster feeding common
Month 1 - 2	80 - 120 mL	80 - 120 mL	7 - 9	600 - 900 mL	150 - 200 mL/kg/day
Month 2 - 3	120 - 150 mL	120 - 150 mL	6 - 8	720 - 1050 mL	Growth spurt at ~3 months
Month 3 - 4	150 - 180 mL	150 - 180 mL	5 - 7	750 - 1100 mL	Peak milk-only intake
Month 4 - 5	150 - 200 mL	150 - 210 mL	5 - 6	750 - 1050 mL	Some begin solids readiness
Month 6 - 7	200 - 240 mL	180 - 240 mL	4 - 6	600 - 900 mL	Solids introduced, milk tapers
Month 8 - 9	240 - 300 mL	180 - 240 mL	3 - 5	500 - 800 mL	2 - 3 solid meals/day
Month 10 - 12	250 - 300 mL	180 - 240 mL	3 - 4	400 - 700 mL	Milk complements solids
Month 12+	300+ mL	150 - 240 mL	2 - 3	300 - 500 mL	Transition to whole milk possible

Frequently Asked Questions

Weight is the primary driver. Two babies of the same age can differ by 1-2 kg, which at a factor of 150 mL/kg/day creates a 150-300 mL/day difference. Age refines the factor (F) because metabolic rate per kilogram decreases as the infant grows. A 3-month-old at 6 kg needs approximately 900 mL/day (150 × 6), while an age-only chart might suggest 720 mL for an average-weight baby. Always use measured weight over age-based estimates.

After 4-6 months, complementary solid foods supply an increasing share of caloric needs. The WHO recommends starting solids at 6 months. By 9 months, solids may contribute 30-50% of total energy. The factor F drops from ~150 to ~100 mL/kg/day to reflect this dietary shift. If your infant is not yet eating solids at 6 months, use the higher end of the 4-6 month range until solids are established.

The AAP suggests a practical ceiling of approximately 960 mL (32 oz) per day for formula-fed infants under 6 months. Exceeding this can cause iron deficiency (excess calcium blocks iron absorption), excessive weight gain, and increased spit-up from stomach over-distension. For breastfed infants, self-regulation typically prevents overfeeding, but pumped bottle feeds should still be paced to avoid exceeding ~1000 mL/day.

Growth spurts typically occur at days 7-10, weeks 2-3, week 6, month 3, month 4, and month 6. During these 2-4 day periods, infants may demand 20-30% more than the calculated baseline. This calculator provides a range (min - max). Use the upper bound during growth spurts. If intake consistently exceeds the maximum range for more than 5 days, re-weigh the baby - the weight has likely increased and a new calculation is needed.

Breast milk averages 65-70 kcal/100 mL. Standard infant formula is calibrated to 67 kcal/100 mL (20 kcal/oz). The caloric density is nearly identical by design, so volume recommendations are equivalent. However, breast milk composition varies throughout the day (foremilk ~60 kcal vs. hindmilk ~80 kcal), so breastfed babies may self-regulate slightly lower volumes. This tool uses a unified volume model but notes that breastfed intake often trends toward the lower end of the range.

The Holliday-Segar formula (100 mL/kg/day for the first 10 kg of body weight) estimates minimum maintenance fluid requirements. It was developed for hospitalized children but serves as a useful safety floor. If the calculated milk intake falls below this threshold - which can happen if an unusually heavy baby is entered with a late age bracket - the tool flags a warning. This does not mean the baby is dehydrated; it means the result should be reviewed with a pediatrician.