1 · Convert weight
15 lb × 0.453592
6.8039 kg
Method, example & sources
How we calculate your baby’s milk estimate
The calculator turns three details—weight, age, and feedings per day—into a daily range and a per-feeding range. This page shows every step, including the rounding and the limits of what the result can tell you.
Return to the calculatorThe calculation
From weight to a daily range.
We calculate a range rather than a single target because babies do not eat exactly the same amount every day.
- 1
Convert the weight to kilograms.
Pounds and ounces are combined, then multiplied by 0.453592. Metric entries are already ready for the next step.
- 2
Apply the age-based ml/kg/day range.
Weight in kilograms × the lower and upper values for the age band gives the 24-hour range in milliliters.
- 3
Divide by feedings and convert units.
Daily milliliters ÷ feedings per day gives the per-feeding range. We divide milliliters by 29.5735 for fluid ounces and display one decimal place.
Age adjustment
Age ranges used by the calculator
The calculator chooses one band from the baby’s total age in months and weeks. These are general reference ranges, not a prescription.
| Baby’s age | Daily range | How to read it |
|---|---|---|
| 0–2 months | 150–180 ml/kg/day | The highest weight-based range, used through the early newborn months. |
| 2–6 months | 120–150 ml/kg/day | The range used in the worked example below. |
| 6–12 months | 100–120 ml/kg/day | Milk remains important while complementary foods gradually begin. |
| 12+ months | 90–110 ml/kg/day | A broad reference only; feeding needs change after the first birthday. |
Follow the numbers
A worked example
Here is the exact path for a 15 lb baby who is 3 months old and has 6 feedings per day.
2 · Apply the 2–6 month range
6.8039 × 120–150
816.5–1,020.6 ml per day
3 · Convert the daily total
÷ 29.5735
27.6–34.5 oz per day
4 · Divide by 6 feedings
daily range ÷ 6
136.1–170.1 ml · 4.6–5.8 oz
Use the range safely
When this estimate is not enough
Treat it as a guide, not a quota
Appetite varies from feeding to feeding. Wet diapers, growth, and feeding cues matter more than matching a single number exactly.
Use a clinician’s individual plan
Prematurity, poor weight gain, dehydration, acute illness, fortified feeds, or medical complexity need individualized advice.
Follow the formula label exactly
The on-page preparation card is an example. Scoop size and water-to-powder ratios vary by brand; use the instructions on your own container.
Recalculate as weight changes
A current weight gives a more useful estimate. Recheck periodically and whenever your pediatrician updates the feeding plan.
Source trail
References
These pediatric and public-health pages inform the age context, feeding frequency, and safety boundaries used to maintain the calculator.
01 · HealthyChildren.org / American Academy of Pediatrics
Amount and Schedule of Baby Formula FeedingsAAP guidance on formula intake by weight and feeding cadence.
02 · CDC
How Much and How Often to Feed Infant FormulaCDC guidance on first days, first months, and 6-12 month formula feeding.
03 · HealthyChildren.org / American Academy of Pediatrics
How Often and How Much Should Your Baby Eat?AAP overview of breast milk and formula feeding frequency and volumes.
04 · World Health Organization
Infant and Young Child FeedingWHO fact sheet covering exclusive breastfeeding, complementary feeding, and continued breastfeeding.
Trust & methodology
A method with a paper trail
The calculation, sources, review date, and correction path live together here so parents can check what sits behind the result.
Last sitewide review
June 11, 2026
Maintained by
Baby Milk Calculator editorial team
Editorial policy
Who writes the site, how sources are chosen, how updates and corrections are handled.
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How we calculate
The intake ranges, unit conversions, and guardrails behind every result.
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Corrections & contact
Send a question or correction to support@milkcalculator.org.
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SourcesAmerican Academy of PediatricsCenters for Disease Control and PreventionWorld Health OrganizationU.S. Department of AgricultureU.S. Food and Drug Administration