About
Built for parents who want clarity
infantgrowthcalculator.com is a free tool that helps parents and caregivers understand how their baby is growing relative to established medical standards — without the confusion of paper charts or paywalled apps.
Our mission
Growth monitoring is one of the most reliable early indicators of infant health. Yet understanding a percentile chart — knowing whether a 25th percentile reading is "good" or "concerning" — is harder than it should be.
We built this tool to make that information transparent, accurate, and free. Every calculation runs entirely in your browser using official WHO and CDC datasets. No data is ever sent to a server. No account is needed.
Why WHO and CDC?
The WHO Child Growth Standards (2006) were derived from a multi-country study of children raised in optimal conditions — breastfed, non-smoking households, adequate nutrition — making them a true international reference for how children should grow.
The CDC Growth Charts (2000) describe how children in the United States actually grew across a broad, representative sample. Pediatricians in the US often use CDC charts for children over 2 years of age.
We include both standards and let you choose — because the right reference depends on your child's age, location, and your pediatrician's preference.
Geography-aware percentiles
Growth patterns vary across populations. Where available, we incorporate country- and region-specific growth references alongside the global WHO standard, so the comparison is as relevant as possible to your child's background.
Your privacy comes first
All calculations happen locally on your device. We do not collect, store, or transmit any health data. The optional multi-child dashboard uses your browser's localStorage — data that never leaves your machine.
Read our full Privacy Policy for details.
Medical disclaimer
infantgrowthcalculator.com is an informational tool only. Percentile values are reference points, not diagnoses. A baby growing at the 5th percentile may be perfectly healthy; a baby at the 95th percentile may warrant investigation. Only a qualified healthcare provider can evaluate your child's growth in context.
Always discuss growth concerns with your pediatrician.
Get in touch
Questions, feedback, or corrections to our data? We'd love to hear from you.