Calc My Baby is a free website that helps parents quickly work out their baby’s age and growth. We built it to answer the everyday questions parents ask, such as how old a baby is in weeks and months, and whether a baby is growing as expected, without sign-ups, downloads or complicated charts to decode.
Our tools include a baby age calculator that gives an exact age in years, months, weeks and days, a baby percentile calculator for weight and length, a height percentile calculator focused on length, and a baby growth chart that shows median weight and length by age at a glance.
All of our growth calculations are based on the WHO Child Growth Standards, the international reference used by pediatricians worldwide. Every calculation runs in your own browser, so the dates and measurements you enter stay on your device — we do not store any baby data.
Calc My Baby is here to give parents clear, reassuring information in seconds. Our calculators are for general information only and are not medical advice. If you ever have concerns about your baby’s health or growth, please talk to your pediatrician, who knows your baby best.