Baby WeightEvery weigh-in, on the curve — and only on your phone.
Baby Weight logs your baby's weight, length, and head circumference and shows WHO growth percentiles instantly. No account, no cloud, no feeding-and-diaper bloat — just growth tracking done right.
In preparation for the App Store and Google Play — not yet downloadable.
From bathroom scale to percentile in seconds
Built for the thirty seconds you actually have with a wriggling baby — a minimal setup, quick entry, and a chart that answers the question you're really asking.
Add your baby
Name, birth date, and sex — that's the whole onboarding. Add a due date if your baby arrived early so charts can use corrected age.
Log a measurement
Weight, length, or head circumference, in kg/cm or lb/in, with an optional note like "after feed" or "at the doctor's office". Edit or delete any entry later.
See where it lands
The dashboard shows the latest numbers with their WHO percentiles, and the charts plot every measurement as its own point against the percentile curves.
The measurements that matter — and nothing else
No feeding timers, no diaper logs, no sleep schedules. Baby Weight tracks the three measurements your pediatrician charts at every checkup.
- Weight
- Logged in kilograms or pounds, charted against WHO weight-for-age percentiles for your baby's sex and age.
- Length / height
- Centimeters or inches, charted against WHO length-for-age percentiles from birth to 24 months.
- Head circumference
- The measurement most apps skip — tracked and charted against WHO head-circumference-for-age references.
- Weight-for-length
- How weight and length relate to each other — the fourth WHO standard chart, included for the full picture.
- Notes
- A free-text note on any measurement — clothed or not, home scale or clinic scale, before or after a feed.
- Multiple children
- Track siblings side by side with a quick child switcher; every child keeps their own history and charts.
Real WHO percentiles, computed the way clinics do it
Percentiles come from the WHO Child Growth Standards (0–24 months) using the LMS method — the same reference data and calculation approach used in pediatric practice.
Points, not connect-the-dots
Each weigh-in is plotted as its own point against the percentile curves, so an odd reading from a home scale doesn't get drawn into a misleading zig-zag line.
- Four chart types — weight-for-age, length-for-age, head-circumference-for-age, and weight-for-length.
- Separate references for boys and girls, exactly as WHO publishes them.
- Percentiles on the dashboard — the latest numbers and where they fall, front and center.
- Dark mode, light mode, or system — for 3 a.m. logging that doesn't wake anyone.
Corrected age for preemies, built in
Comparing a baby born at 32 weeks against full-term charts understates their growth. Add a due date and Baby Weight computes corrected age — the age your baby would be if born at term — and uses it for every percentile lookup, following the practice commonly used for preterm infants during the first two years.
Read more in our guide: corrected age for premature babies, explained.
Walk into the checkup with the chart in hand
Your records are useful only if you can show them — and only if you can't lose them.
PDF report and local backup
- PDF growth report — every measurement with its WHO percentile in a clean, printable report you can share before or during a visit.
- Local backup file — export all your data as a single file to your Files app or anywhere you choose, and restore it on a new phone.
- No silent cloud sync — nothing is uploaded unless you explicitly share a file.
- Edit history safely — fix a mistyped weight without losing the original entry date.
Your baby's data belongs in your pocket, not a database
Baby-tracking apps have a poor privacy track record as a category. Baby Weight takes the simplest possible position: your measurements are stored only on your device. There is no account, no server, no analytics SDK, and no advertising identifier — so there is nothing to breach, sell, or subpoena.
- No account · ever
- No cloud · local storage only
- No trackers · zero analytics
- No ads · nothing to fund with data
Understand the chart before the checkup
Plain-English, evergreen guides to baby growth tracking — written from WHO, CDC, and AAP public references, with sources linked.
- Baby growth percentiles, explainedWhat the 30th percentile actually means — and doesn't mean.
- Newborn weight gain: what's typicalThe early dip, the regain, and what pediatricians look for.
- Corrected age for preemiesHow to chart a baby who arrived early, and until when.
- Weighing your baby at homeGetting consistent readings from imperfect scales.
- Why baby-app privacy mattersWhat tracking apps collect, and how to choose a private one.
Questions parents ask
When is Baby Weight available?
Baby Weight is being prepared for the App Store and Google Play and is launching soon. It is not downloadable yet. Once live, it will be available for iPhone, iPad, and Android.
Which growth charts does Baby Weight use?
Baby Weight uses the WHO Child Growth Standards for ages 0–24 months: weight-for-age, length-for-age, head-circumference-for-age, and weight-for-length, with separate reference data for boys and girls. Percentiles are calculated with the standard LMS method published by WHO and CDC.
Does Baby Weight support premature babies?
Yes. Add your baby's due date and Baby Weight calculates corrected age — the age your baby would be if born at full term — and uses it when looking up percentiles, following the common practice for preterm infants during the first two years.
Is my baby's data private?
Yes. All measurements are stored locally on your device. There is no account to create, no cloud upload, and no analytics or advertising trackers. Data leaves your phone only when you choose to export or share it, for example as a PDF report or a local backup file.
Can I track more than one child?
Yes. Baby Weight supports multiple children with a quick switcher, and each child keeps their own measurement history, charts, and percentiles. Both metric (kg/cm) and imperial (lb/in) units are supported.
Can I share measurements with my pediatrician?
Yes. Baby Weight generates a clean PDF growth report that lists your baby's measurements alongside their WHO percentiles, ready to share or print before a checkup. You can also save a local backup file of all your data.
Is Baby Weight medical advice?
No. Baby Weight is an information and record-keeping tool, not a medical device, and it does not provide medical advice or diagnosis. Growth percentiles are reference statistics, not judgments about your baby's health. Always discuss your baby's growth with your pediatrician or health visitor.