Tall or nah for doctors—a simple way to help families understand height percentiles.

Tall or Nah is a free, doctor-and-patient-friendly height calculator that uses CDC growth-reference data to show where a child or adolescent's height falls relative to the U.S. reference population.

For growing children, Tall or Nah can also project adult height using percentile tracking, the most accurate way to predict a person's end height. And the minimum age Tall or nah can calculate is 2 years old!

Try Tall or nah

Tall or nah is 100% free—and always will be. Try it now!

Why use Tall or nah?

When parents ask if their child is tall or short for their age and biological sex, the clinical answer involves a statistical computation of height percentiles. Tall or Nah turns that challenge into something both doctors and families can easily do themselves.

Tall or nah doesn't replace the CDC Growth Charts—it turned them into an easy-to-use calculator. Tall or nah is powered by the very 19-year, multi-million-dollar survey that produced the CDC Growth Charts.

How it works

First, enter the child's information into the calculator:

• Current height (feet and inches or centimeters)
• Biological sex
• Year and month born

Then hit the button to see their height percentile—the percentage of their peers they're taller than. And if they're still growing, you will see their projected adult height—more technically, the mean average of their individual genetic height potential.

It's that easy! It's also really fun!

Accuracy

The data that powers Tall or nah is staggeringly accurate. Don't let the name fool you, what you are accessing here is, in actuality, one of the most authoritative datasets in American pediatric health.

The dataset that powers Tall or nah comes from 19 cumulative years of data collection that was funded and overseen by the National Center for Health Statistics in the United States. The study, which spanned four consecutive decades, measured the heights of tens of thousands of people across every major racial and ethnic group in America from infancy to adulthood. It was this landmark survey that produced the CDC Growth Charts.

And it is this very data that powers every Tall or nah calculation.

When this can be useful in practice

• When a parent asks if their child is tall or short for their age and biological sex.
• When a parent asks how tall their child will be as an adult.
• When a parent or patient wants to know how to grow taller.
• When a parent or patient wants to learn more about height.

Height Advantage

While the height calculator is the bread and butter of Tall or nah, Height Advantage: The Ultimate Guide to Unlocking Max Height is a remarkable additional resource.

This guide answers conceivably every question a parent or patient might have about height—their own or their children's. Height Advantage is a precious resource for anyone interested in reaching the upper limit of their individual genetic height potential.

What's the catch? Does Tall or nah sell user data?

Absolutely not! Tall or nah doesn't even collect data, let alone sell it. All of the data that is entered into Tall or nah is used strictly to make height calculations. The moment you close the web browser, that calculation is gone forever.

Tall or nah is funded entirely by family-friendly ads, just like your favorite free medical journal.

For clinicians who want to learn more

The Tall or nah website is rich in literature about how the calculator works, the data that powers the calculator, and supporting information about height, statistical modeling, and more. If you want to learn more about Tall or nah and whether it's right for you or your patients, we encourage you to look around the website. We're confident all of your questions will be answered.

Ready to get started?

Hit the button below and help families understand their child's height!