Baby Formula Calculator

Baby's weight

Age in months

Feeds per day

Estimated daily intake

Amount per feed

Based on the common guideline of about 2.5 oz (150 ml) per pound of body weight per day for babies under 6 months, tapering off as solid foods are introduced, and capped around 32 oz (960 ml) per day. This works for formula or expressed breast milk. Premature babies often need a different feeding volume and schedule set by their care team, so treat this as a starting point, not a substitute for their guidance. Every baby is different — follow hunger and fullness cues, and check with your pediatrician about your specific feeding plan.

How this is calculated

This calculator scales feeding volume by body weight, using roughly 150 mL (about 2.5 oz) per kilogram per day for babies under 6 months, stepping down to about 120 mL/kg/day between 6–9 months and 100 mL/kg/day from 9–12 months as solid foods start replacing some liquid intake. The total is then capped around 960 mL (32 oz) per day, and divided evenly across however many feeds per day you enter to estimate an amount per feeding session.

This kind of weight-based, age-tapered guideline is a widely cited starting point in general pediatric feeding guidance, not a precise formula unique to any one baby. It works whether you're measuring formula or expressed breast milk, since both are typically dosed by volume in the same way.

Directly breastfed babies don't fit neatly into this math at all, since there's no bottle to measure — for them, the number of wet and dirty diapers, steady weight gain, and general contentment after a feed are the usual signs that intake is adequate, rather than a volume figure like the one this calculator produces.

Common edge cases and things to know

Appetite varies a lot from baby to baby and day to day — growth spurts (common around 2–3 weeks, 6 weeks, 3 months, and 6 months) can temporarily push intake above what a formula like this predicts, while a baby who's unwell or teething may eat less for a stretch. Treat the number here as a ballpark, not a target your baby must hit at every single feed.

Premature babies very often need a different volume and feeding schedule, set and adjusted by their care team based on corrected age and catch-up growth goals, so this general calculator is a poor substitute for that individualized plan. Babies who are mixed-fed (some breast, some bottle) don't need to hit the full bottle-only volume shown here, since expressed or direct breastfeeding isn't measured the same precise way. And once solids are well established, usually from around 6 months, total liquid intake naturally drops even though this calculator's formula keeps scaling by weight — follow your baby's cues over the math at that stage.

It's also worth remembering the daily cap built into this calculator is a general ceiling, not a per-baby prescription — a bigger or more active baby may comfortably drink close to it, while a smaller baby may be perfectly well-fed on noticeably less. If your baby consistently seems hungrier or fuller than the numbers here suggest, that's worth mentioning at your next pediatric visit rather than adjusting the plan on your own.

Sources

General infant feeding guidance is published by HealthyChildren.org (from the American Academy of Pediatrics), the World Health Organization, and Mayo Clinic.