The baby growth tracker
that shows you exactly
how well they are thriving.
Lunara's baby growth tracker plots your child's weight, height, and head circumference on WHO-standard percentile curves in real time — giving you the same data your pediatrician uses, updated after every measurement. Trusted by 2.4 million families, it is the only baby growth tracker app that connects growth data with sleep patterns and feeding logs to explain the why behind every growth spurt, plateau, and percentile shift.
📈 WHO-standard charts · 🔒 Free to start · 2.4M families
Your baby is in the 40th percentile.
That does not mean what you think.
The most common question pediatricians hear after a growth check-up is: "Is the 40th percentile good?" The answer every time is yes — as long as your baby is following their own curve consistently.
Percentiles are not grades. They do not rank babies against each other in terms of health. The WHO Child Growth Standards — used in over 140 countries — describe how children grow when given optimal conditions. A baby on the 15th percentile for weight who consistently follows their own curve is growing exactly as expected. A baby who drops two major percentile lines in three months may warrant a conversation with your pediatrician — regardless of their current number.
This is what Lunara's baby growth tracker monitors. Not the number in isolation, but the pattern over time. The direction of travel. The consistency of the curve. Because that is what your pediatrician is actually looking at — and now you can see the same picture they see. The CDC growth chart and AAP growth guidelines point to the same conclusion: consistency matters more than any single percentile reading.
See how feeding patterns connect to growth trends →Weight, height, and head circumference — logged in seconds, plotted for life.
Your pediatrician tracks three measurements at every well-baby visit: weight, length or height, and head circumference. Each tells a different story about your baby's development. Together, they create the most complete picture of growth that exists.
Lunara's baby weight tracker, baby height tracker, and head circumference tracker work as one unified system. Log a measurement with a single tap — Lunara plots it on the correct WHO percentile curve instantly, calculates your baby's current percentile ranking, and shows how the measurement compares to your baby's own historical curve.
For parents with preterm babies, Lunara automatically applies gestational age correction to all three measurements — a detail that many generic growth chart apps miss entirely, and one that makes a significant difference in how growth data should be interpreted.
- Weight tracking: kg and lb, plotted on WHO weight-for-age
- Height tracking: cm and inches, plotted on WHO length-for-age
- Head circumference: plotted on WHO head circumference chart
- BMI-for-age calculation (from 2 years)
- Gestational age correction for preterm babies
- Metric and imperial unit switching in one tap
The same charts your pediatrician uses. Updated after every measurement.
The WHO Child Growth Standards, published in 2006 after a multi-country study across six countries, represent the most rigorous and widely adopted growth reference data available. They describe how children grow under optimal conditions — regardless of ethnicity, country, or feeding method — and are now used in over 140 countries as the global standard for child growth monitoring.
Lunara uses WHO growth standards as the foundation for all percentile calculations. When you log your baby's weight, height, or head circumference, Lunara plots it against the WHO reference curves in real time — the same curves your pediatrician uses at every well-baby visit. You see what they see. You understand what they see. And you arrive at every appointment fully informed.
For parents in the United States, Lunara also offers CDC growth charts as an optional reference standard — the same charts recommended by the CDC for children over 2 years of age. You can switch between WHO and CDC standards with one tap.
- WHO Child Growth Standards (2006) — default for 0–5 years
- CDC growth charts — optional for children 2 years+
- Percentile lines: 3rd, 15th, 50th, 85th, 97th displayed
- Your baby's curve plotted alongside reference lines
- Switch between metric and imperial measurements
- Historical data preserved — full growth history maintained
Growth spurts happen fast. Lunara sees them coming.
A baby growth spurt typically lasts 2–3 days but can disrupt feeding, sleep, and routine for an entire week around it. Parents experience increased hunger cues, disrupted sleep, and unexplained fussiness — and usually do not know why until the spurt has already passed.
Lunara's AI baby growth tracker cross-references your baby's sleep data, feeding frequency, and weight measurements simultaneously. When the pattern matches the signature of an approaching growth spurt — increased feeding demand alongside a temporary sleep disruption, typically 2–4 days before a measurable weight gain — Lunara sends a calm, plain-language alert. Learn more about how sleep tracking connects to growth patterns.
Major growth spurts typically occur at: 7–10 days, 2–3 weeks, 4–6 weeks, 3 months, 4 months, 6 months, and 9 months. Lunara is calibrated to all seven windows and connects the disruption you are feeling today with the growth you will see on the scale in three days.
- Detects all 7 major growth spurt windows automatically
- Cross-references sleep + feeding + weight data
- Alert arrives 2–4 days before measurable weight gain
- Plain-language explanation of what to expect
- Post-spurt confirmation when weight gain is measured
Lunara's growth spurt alerts are informational and do not constitute medical advice. Always consult your pediatrician with any concerns about your baby's growth.
Walk into every check-up fully prepared.
Every well-baby visit, your pediatrician will ask about feeding frequency, sleep patterns, growth measurements, and developmental milestones. Most parents answer from memory — which is unreliable when you are running on three hours of sleep.
Lunara generates a one-tap growth report that includes your baby's complete measurement history, WHO percentile curves with your baby's data plotted, a growth velocity summary, and a feeding and sleep overview — formatted specifically for pediatric review. Your doctor gets the data they need. Your visit is more productive. Your baby gets better care.
The report exports as a PDF in under 10 seconds and can be shared directly from the app via email or message — no printing required.
Your baby's growth starts with what they eat.
Growth and feeding are inseparable. A baby who is not feeding adequately will not grow adequately — and a baby who is growing through a spurt will feed more frequently than their established pattern. Lunara is the only baby growth tracker that makes this connection explicit.
When your baby's weight curve slows unexpectedly, Lunara cross-references feeding logs from the same period — surfacing whether reduced feeding frequency preceded the plateau. When a growth spurt begins, Lunara connects the increased feeding demand with the weight gain that follows — so you understand why your baby is suddenly feeding every 90 minutes instead of every three hours.
This cross-referencing is available for breastfed, formula-fed, and weaning babies alike. Every feeding method is supported. Every correlation is explained in plain language.
- Weight plateau cross-referenced with feeding logs
- Growth spurt feeding surge — detected and explained
- Supports breastfeeding, formula, and solid foods
- Feeding adequacy indicator — based on WHO guidelines
- Weekly feeding and growth correlation summary in AI digest
What is typical growth at every age — according to WHO and AAP.
Every age brings different growth expectations. Tap your baby's age to see WHO-standard ranges, what to watch for, and how Lunara tracks each stage.
Newborn growth tracker
1-month baby growth
2-month baby weight and growth
4-month baby growth milestones
6-month baby growth — halfway to one year
9-month baby growth and development
12-month baby growth — first birthday
Toddler growth tracker — 2 years and beyond
The baby growth tracker alternative your pediatrician will notice.
Many baby apps include a basic weight log. Fewer include WHO growth charts. None connect growth to feeding and sleep the way Lunara does. Here is exactly what separates Lunara from the alternatives parents switch from.
| Feature | Lunara | Huckleberry | Glow Baby | CDC Chart |
|---|---|---|---|---|
| WHO growth charts | ✓ Full | ✓ Basic | ✓ Basic | ✗ |
| CDC growth charts | ✓ Switchable | ✗ | ✗ | ✓ Online |
| Weight + height + head circ. | ✓ All 3 | ✓ All 3 | ✓ All 3 | ✗ |
| BMI-for-age tracking | ✓ 2yr+ | ✗ | ✗ | ✗ |
| AI growth spurt detection | ✓ | ✗ | ✗ | ✗ |
| Feeding + growth correlation | ✓ | ✗ | ✗ | ✗ |
| Growth spurt alert (advance) | ✓ 2–4 days | ✗ | ✗ | ✗ |
| Gestational age correction | ✓ Preterm | ✗ | ✗ | ✗ |
| Pediatrician PDF report | ✓ | ✗ | ✗ | ✗ |
| Historical curve over time | ✓ Full | ✓ Limited | ✓ Basic | ✗ |
| Free tier | ✓ Generous | ✓ Limited | ✓ Limited | ✓ Free |
| Pricing | $0–$9/mo | $9.99/mo | Free+ads | Free |
When the chart tells you everything is fine.
"My daughter was on the 8th percentile and I was convinced something was wrong. Lunara showed me her curve — she had been tracking perfectly along the 8th percentile since birth, never dropping, never surging. Our pediatrician confirmed it. Lunara gave me that peace three weeks before our appointment."
"The growth spurt alert changed everything for us. Lunara told me a spurt was coming 3 days before my son went into feeding overdrive. Instead of panicking at the cluster feeding, I just… knew. That one feature alone is worth the subscription."
"I brought the Lunara growth report to our 6-month check-up. Our pediatrician spent 30 seconds reviewing it and said it was the most complete growth history she had seen from a non-clinical source. She asked me to keep using it."
Everything about the baby growth tracker
Lunara is the highest-rated baby growth tracker app, with a 4.9-star average from 142,000 verified reviews. It plots weight, height, and head circumference on WHO-standard percentile curves in real time, detects growth spurts 2–4 days in advance, and generates a one-tap PDF report formatted for pediatrician review — features no other free baby growth tracker offers.
Log your baby's weight, length, and head circumference in the Lunara app after each measurement — at home or after a pediatric visit. Lunara instantly plots each measurement on WHO growth charts, calculates the current percentile, and shows the trend against your baby's own historical curve. A kitchen scale and a soft tape measure are all the equipment you need.
A growth percentile describes where your baby falls relative to the WHO reference population at the same age. A baby in the 40th percentile for weight means 40% of babies the same age weigh less, and 60% weigh more — it does not mean the baby is unhealthy. What matters most is consistency: a baby following their own curve, whatever percentile it sits at, is growing exactly as expected.
According to WHO guidelines, typical weight gain is: 150–200g per week in the first month, 100–150g per week from months 2–4, 70–100g per week from months 4–6, and 40–70g per week from months 6–12. Lunara calculates your baby's growth velocity automatically and compares it to WHO reference ranges after every measurement.
The most reliable indicator of normal growth is a consistent percentile curve over time — not the percentile number itself. According to the AAP, a concern arises when a baby crosses two major percentile lines in either direction over two consecutive measurements. Lunara monitors your baby's curve automatically and flags significant deviations while explaining what they mean.
The WHO Child Growth Standards are a set of international growth reference charts published in 2006 following a multi-country study across six countries. They describe how children grow under optimal conditions and are now used in over 140 countries as the global standard for growth monitoring. Lunara uses WHO standards as the default reference for all growth charts from birth to age 5.
Measure your baby's head circumference with a soft tape measure at the widest point — above the eyebrows and ears, around the back of the head. Log the measurement in Lunara's head circumference tracker. Lunara plots it on the WHO head circumference-for-age chart and calculates the current percentile, flagging any significant deviation from your baby's established curve.
Discuss your baby's growth with your pediatrician if they have not regained birth weight by 2 weeks, are crossing two or more major percentile lines downward over consecutive measurements, show a sudden unexplained acceleration in head circumference, or appear to have stopped growing over a 4-week period. Lunara flags these specific patterns and provides the exact data point to raise at your next check-up — calmly and specifically.
A growth spurt is a period of accelerated growth during which babies feed more frequently, may sleep more or less than usual, and gain weight rapidly over 2–3 days. Major growth spurts occur at 7–10 days, 2–3 weeks, 4–6 weeks, 3 months, 4 months, 6 months, and 9 months. Lunara's AI growth tracker detects the feeding and sleep pattern shifts that precede each spurt and alerts you 2–4 days in advance.
Yes. Lunara generates a comprehensive growth report that includes complete measurement history, WHO percentile curves with your baby's data plotted, a growth velocity summary, and a feeding and sleep overview — all formatted for pediatric review. The report exports as a PDF in under 10 seconds and can be shared directly via email or message from within the app.
The WHO Child Growth Standards (2006) describe how children grow under optimal conditions globally and are recommended for children from birth to age 5. The CDC growth charts (2000) are based on US survey data and are recommended by the CDC for children aged 2 years and older in the United States. Lunara offers both standards — WHO as the default, with CDC charts available as an optional switch for children aged 2 and above.
Lunara's growth tracking accuracy depends on the accuracy of the measurements entered. When measurements are taken correctly — weight on a calibrated scale, length on a flat surface, head circumference with a non-stretch tape — Lunara's WHO percentile calculations match clinical standards exactly. Lunara also applies gestational age correction for preterm babies automatically, which many generic growth apps miss.
See exactly how well
your baby is thriving.
Join 2.4 million families using the free baby growth tracker app that plots WHO-standard charts, detects growth spurts early, and prepares you for every pediatrician visit. Start in 60 seconds.
📈 WHO-standard charts · 🔒 Free forever · No card needed