Baby Growth Percentile Calculator
Our growth percentile calculator shows how your baby's size compares with other boys or girls the same age. Just enter your child's weight, height (aka length), and head circumference, and we'll calculate a percentile for each.
Key Takeaways
Using Our Baby Growth Chart
When your baby is first born, you'll have several visits at your pediatrician's office to make sure your little one's growth is on track. Your pediatrician will plot your baby's weight, height, and head circumference on a growth chart.
A baby growth chart helps you and your pediatrician keep track of how your baby's growing. Consistent growth is a sign that your baby is healthy.
Don't be concerned if your child doesn't fall right in the middle of the growth chart, though. There's a wide range of normal, and your baby's measurements now don't necessarily reflect what size they'll be as an adult.
Understanding Percentiles: Percentiles show how your child's weight, height, and head circumference compare to other children who are the same age and sex. For example, if your child's weight is in the 20th percentile, they weigh more than 20 percent of children their age and sex.
It's normal for some children to be in the 10th percentile for weight, while others are in the 90th percentile. The most important thing is that your baby is growing at a healthy and consistent rate, no matter what percentile they're in.
Our growth percentile calculator is an educational tool only. It's not the last word on how your child is growing, and it's not a substitute for having a healthcare provider monitor your child's growth at regularly scheduled exams. At these visits, your pediatrician will determine whether your child is following a healthy growth pattern over time.
Important Note: This tool is for children under age 2 and is based on World Health Organization data for kids in that age group. You can also find out how tall your older child is likely to be with our Child Height Predictor.
Read on to learn more about the measurements healthcare professionals take, and how to measure your baby at home.
What Makes Our Calculator Special
Interactive Growth Charts
Visualize your baby's growth with color-coded percentile ranges and animated charts that make tracking development easy and intuitive.
Dual-Unit Support
Switch seamlessly between metric (kg/cm) and imperial (lb/in) units. Perfect for families who prefer either measurement system.
Historical Tracking
Save and compare measurements over time to see your baby's growth trajectory and identify patterns in their development.
Smart Insights
Get personalized feedback and contextual messages based on your baby's measurements, with color-coded indicators for easy understanding.
Developmental Milestones
Learn about age-appropriate milestones alongside growth metrics to get a complete picture of your baby's development.
Mobile-Friendly
Access the calculator from any device, whether you're at home or on-the-go, with a responsive design that works everywhere.
How to Measure Your Baby at Home
Baby Weight
If you want to see how your baby is growing between doctor's visits, here's how to get a fairly accurate weight at home:
- Undress your baby completely (remove the diaper too) and step on a scale while you're holding your child. Record that weight.
- Set your baby down and weigh yourself. Subtract your own weight from your combined weight with your baby and record that number.
Note: This isn't as accurate as weighing your baby at the doctor's office, but it's a good estimate of how much your little one weighs.
When to Call Your Pediatrician: If you're worried about your baby's weight gain, call your baby's pediatrician. They may have you come in for a visit, since it's important to have your baby weighed on a consistent scale that can accurately measure weight in pounds and ounces.
Baby Height (Length)
Before your baby can stand and walk on their own, height is often recorded as "length" – that is, how long your baby is from the crown of the head to the bottom of the heel while lying down.
How to measure at home:
- Lay your baby down on a flat surface and stretch a measuring tape from the top of the head to the bottom of the heel. Since babies' knees naturally bend a bit, you may need a second person to stretch out their legs while you take the measurement.
- Record your child's length to the nearest tenth of a centimeter or inch. (In the hospital, birth length is often recorded in centimeters, but your pediatrician's office will likely record baby length in inches. What you do is up to you!) Your record might be a little different than the doctor's, but that's okay.
Baby Head Circumference
Your baby's healthcare provider will measure head circumference for the first two years of your child's life to make sure your baby's brain is growing at a healthy rate.
You can measure your baby's head circumference at home too, but it can be hard to do accurately. Here's how to get a good estimate:
- Wrap a flexible measuring tape around the widest part of your baby's head, just above the eyebrows and ears and around the back, where the head slopes out from the neck.
- Take the measurement three times (your baby may be wiggly, which could make getting an accurate measurement tough) and use the largest measurement to the nearest tenth of a centimeter.
How This Tool Helps Moms and Families
Peace of Mind Between Doctor Visits
Waiting for the next pediatrician appointment can feel like a long time, especially in those early months when your baby is growing so rapidly. Our calculator lets you check in on your baby's development whenever you want, giving you reassurance that everything is on track.
Easy-to-Understand Visual Feedback
Instead of trying to interpret complex medical charts, our tool presents information in a clear, color-coded format:
- Green zone (25-75th percentile): Your baby is within the typical range
- Yellow zone (10-25th or 75-90th percentile): Worth monitoring, but often normal
- Orange zone (below 10th or above 90th percentile): Consider discussing with your pediatrician
Track Growth Over Time
Our historical tracking feature lets you save measurements from multiple dates, so you can see your baby's growth trajectory over weeks and months. This helps you identify whether your baby is growing consistently, which is more important than any single measurement.
Learn as You Go
The calculator includes educational content about developmental milestones, feeding recommendations, and common growth concerns. You're not just getting numbers – you're learning about your baby's development at every stage.
Reduce Anxiety with Context
Every baby grows at their own pace, and our tool provides context-sensitive messages to help you understand what's normal. Whether your baby is petite or robust, you'll get reassurance that there's a wide range of healthy growth patterns.
Prepare for Doctor Appointments
By tracking measurements at home, you can come to your pediatrician appointments with questions and observations. This helps make the most of your limited time with the doctor and ensures important concerns don't get overlooked.
Ready to Track Your Baby's Growth?
Start using our baby growth percentile calculator today and gain valuable insights into your child's development. It's free, easy to use, and designed with busy parents in mind.
Try the Calculator Now📋 Important Disclaimer
This baby growth percentile calculator is an educational tool designed to help you understand your child's growth patterns. It should never replace professional medical advice or regular check-ups with your pediatrician.
Every child is unique, and growth charts represent broad statistical averages. Your pediatrician considers many factors beyond percentiles when assessing your child's health, including:
- Overall health and well-being
- Family genetics and growth patterns
- Feeding history and nutrition
- Developmental milestones
- Any medical conditions or concerns
Always consult your healthcare provider if you have any concerns about your baby's growth or development.