Height Calculator

This online height calculator is an interactive tool that helps you estimate your child’s future adult height. You enter basic input data: the child’s age, gender, current height and weight, plus each parent’s height. The calculator then uses a growth-related, age-based formula (such as mid-parental height and Khamis-Roche) to calculate an adult height prediction. It also compares your child’s current measurement to standard percentile curves (WHO/CDC) and displays an estimated height result and likely range.

The mid-parental height formula is a simple genetic prediction method that uses both parent heights to estimate a child’s adult height:

• For boys: (Father’s height + Mother’s height + 5 inches) ÷ 2
• For girls: (Father’s height + Mother’s height − 5 inches) ÷ 2

This method assumes that genetics and family growth patterns strongly influence the expected adult height. In metric units, 5 inches is about 13 cm.

The Khamis-Roche method is a more advanced, predictive approach. It analyzes several growth-related factors: your child’s age, current height and weight measurements, gender, and both parents’ heights. Because it combines genetic information with real-time development data, it can often determine a more accurate adult height estimation than mid-parental height alone. That’s why this method is usually recommended for children between 4 and 17 years old.

No height calculator can predict adult height with 100% accuracy, but it provides a realistic estimation and output range. For most healthy children, the final result falls within about ±4 inches (±10 cm) of the calculated value. The accuracy of the prediction depends on many factors: genetics, nutrition, sleep, hormones, and overall childhood development. Think of it as an informed estimate, not a guarantee.

The prediction is gender-specific because boys and girls have different growth patterns and different average adult heights. When you select “Boy” or “Girl,” the calculator can use the correct age-based growth curves and gender-specific formulas. This helps the tool assess and compare your child’s height against the right percentile standards and improves the accuracy of the expected adult height.

Both WHO and CDC charts are growth-related references, but they are based on different populations and measurements:

• WHO standards describe how children grow under ideal conditions across multiple countries and are often used for global comparison.
• CDC standards are based on average development patterns in children from the United States.

By allowing you to select WHO or CDC, the calculator lets you compare your child’s height output to different percentile references using the same unit system (ft/in or cm).

Most girls reach their major growth spurt around 11–13 years of age and approach their expected adult height by about 15–16 years. Boys typically have their main spurt later, around 13–15 years, and usually finish growing closer to 17–18 years of age. These are age-based averages, and normal childhood development can vary, so some children finish earlier or later than this range.

Yes. Even though the formula uses parent heights and genetics to predict future height, a child can end up either taller or shorter than both parents. A child might exceed the expected height if they inherit tall genes from extended family or experience very healthy growth and development. Conversely, health issues, nutrition, or hormonal factors can adjust the final result downward. The calculator’s prediction gives a likely estimation, not a strict limit.

Current height and weight are key measurements that show where your child sits on the age-based growth curve today. When you input these values and use a method like Khamis-Roche, the tool can analyze whether your child’s development is ahead of, behind, or close to the average percentile for their age and gender. This helps the calculator track growth, adjust the prediction, and display a more personalized adult height estimation.

This is a user-friendly, interactive, online height calculator designed to estimate and display likely adult height outputs based on growth-related data. It is not a substitute for a medical assessment. If the result is very different from the average for your child’s age and gender, or if you’re concerned about their development, it’s best to consult a pediatrician or endocrinologist. They can measure, assess, and analyze growth more deeply and determine whether any further evaluation is needed.