Infant Formula Amount Calculator
Estimate how much formula a baby needs per day and per feeding from body weight, using the common 2.5 oz-per-pound rule.
How it works
Daily formula (oz) = weight (lb) × 2.5, capped at ~32 oz · Per feeding = daily ÷ feedings/day
A widely used pediatric rule of thumb is that a formula-fed baby drinks about 2.5 ounces per pound of body weight over 24 hours, up to a practical ceiling of around 32 ounces a day. Dividing that daily total by the number of feedings gives a starting amount per bottle. Treat it as a guide, not a quota — babies self-regulate, so follow hunger and fullness cues rather than forcing a target.
Worked example
A 10 lb baby: 10 × 2.5 = 25 oz per day. Split across 6 feedings, that is about 4.2 oz (≈123 mL) per bottle.
Frequently asked questions
What if my baby wants more or less than this?
That is normal. The 2.5 oz-per-pound rule is an average; healthy babies vary day to day. Watch for steady weight gain and wet diapers, and let the baby stop when full rather than finishing every bottle.
Does this replace breast milk amounts?
This is for formula. Breastfed babies regulate their own intake at the breast; if you are bottle-feeding expressed milk, use the breast milk intake calculator instead.
When do babies start needing less formula per pound?
As solids are introduced around 6 months, formula intake per pound gradually falls. By the first birthday most of a child’s calories come from food and milk changes again — ask your pediatrician.
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This is a general educational estimate, not medical advice. Every child grows, feeds and responds to medicine differently — for anything about your child’s health, growth, nutrition or medication, follow the guidance of your pediatrician.