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Baby math, solved in seconds.
The same way we review gear — accurate, source-backed, no fluff. Each calculator shows the formula it uses and runs entirely in your browser, so nothing you type is saved or sent anywhere.
Feeding
Baby Formula Feeding Calculator
How many ounces of formula your baby needs a day, and how much goes in each bottle — from a weight.
2.5 oz / lb / dayOpen tool
Pregnancy
Pregnancy Due Date Calculator
Your estimated due date, current week, and trimester — from the first day of your last period.
Naegele's rule · +280 dOpen tool
Budgeting
Diaper Cost & Quantity Calculator
How many diapers — and how many dollars — from any age to potty training, with a stage-by-stage breakdown.
Σ(days × per-day)Open tool
These calculators are for planning and information only — not medical advice. Always check with your pediatrician or prenatal provider about your child’s needs. How we work.