Predict your child's adult height with our free height calculator. Uses mid-parental height formula and CDC growth data. Includes height percentiles and charts.
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Predicting how tall a child will grow is one of the most common questions parents ask. This height calculator uses scientifically validated methods including the mid-parental height formula and CDC growth chart data to estimate a child's predicted adult height. Enter the parents' heights to get an instant prediction with a height range, or use the percentile calculator to see how your child compares to other children their age.
The mid-parental height formula is the most widely used method to predict a child's adult height based on their parents' heights. It works by averaging the parents' heights and adjusting for the child's sex. For boys, add 5 inches (13 cm) to the mother's height before averaging. For girls, subtract 5 inches (13 cm) from the father's height before averaging. This gives a predicted height with a margin of error of about ±3.4 inches (8.5 cm). While not perfectly precise, this method provides a reliable estimate that pediatricians worldwide use as a first assessment.
Mid-Parental Height Formula
Boys: (Mother's Height + Father's Height + 13 cm) ÷ 2 | Girls: (Mother's Height + Father's Height − 13 cm) ÷ 2Get a science-based estimate of how tall your child will be when fully grown, based on established pediatric formulas used by doctors worldwide.
See how your child's height compares to other children the same age and sex using CDC growth chart data from national health surveys.
If your child falls below the 5th percentile or above the 97th, it may indicate a need for pediatric evaluation. Early detection of growth issues leads to better outcomes.
Unlike bone age methods that require medical imaging, the mid-parental height formula and percentile calculations need only basic measurements you can take at home.
See results from both the mid-parental height formula and growth percentile data to get a more complete picture of your child's growth trajectory.
Learn when boys and girls typically stop growing, what factors affect height, and what range of heights is normal for your child's predicted outcome.
Easily convert between centimeters, meters, feet, and inches. Helpful when medical records use different measurement systems.
Expecting parents can use the mid-parental height formula to get a rough idea of their baby's future adult height based solely on their own heights.
Doctors routinely use mid-parental height and growth percentiles during check-ups to assess whether a child is growing normally.
Teenagers wondering 'how tall will I be?' can enter their current age and height to see a predicted adult height and when they'll likely stop growing.
Parents and coaches can estimate a child athlete's adult height to help with long-term sports development and position planning.
If a child's height percentile is unusually low or high, it may prompt further medical evaluation for conditions affecting growth.
Compare predicted heights for siblings or see how a child's predicted height compares to family members and population averages.
Quickly convert heights between feet/inches and centimeters for medical records, travel documents, or international communication.
Your predicted adult height depends primarily on your parents' heights (genetics accounts for 60-80%). Use the mid-parental height formula: for boys, add your parents' heights plus 5 inches then divide by 2. For girls, add parents' heights minus 5 inches then divide by 2. The result has a margin of error of about ±4 inches.
The most accurate non-clinical method is the Khamis-Roche formula (±2.1 inches for boys, ±1.7 inches for girls), which uses current height, weight, and parents' heights. For clinical precision, bone age X-rays combined with the Bayley-Pinneau method are most accurate. The mid-parental height formula is the simplest with ±4 inches accuracy.
Use the mid-parental height formula: For boys: (mother's height + father's height + 5 inches) ÷ 2. For girls: (mother's height + father's height − 5 inches) ÷ 2. For example, if mom is 5'4" and dad is 5'10", a boy's predicted height = (64 + 70 + 5) ÷ 2 = 69.5 inches = 5'9.5".
Most boys stop growing in height around age 16, though some continue until 18. Boys typically enter puberty at 12-15, and the most significant growth spurt happens 2 years after puberty begins. As a general rule, boys stop growing about 4 years after entering puberty.
Most girls reach their adult height by age 14-15, or about 2 years after their first menstrual period. Girls typically enter puberty earlier than boys (around ages 10-13), which is why they often stop growing earlier.
Yes, about 60-80% of your height is determined by genetics. The remaining 20-40% is influenced by environmental factors, primarily nutrition during childhood and adolescence. Think of genetics as setting your maximum height potential, while nutrition and health determine whether you reach it.
The average height for a 12-year-old boy is about 4 feet 11 inches (149 cm), and for a 12-year-old girl about 4 feet 11.5 inches (151.5 cm). Girls are often slightly taller at this age because they enter puberty earlier.
To find your child's height percentile, enter their age, sex, and current height in our percentile calculator. The 50th percentile means average — half of children that age are taller, half are shorter. The normal range is generally between the 5th and 95th percentiles.
For most people, no. Growth plates in the bones close during late adolescence (typically 14-16 for girls, 16-18 for boys). Once closed, bones can no longer lengthen. However, some men may grow slightly until age 20-21. Daily height can vary up to 1 inch due to spinal disc compression.
Children typically grow 2-3 inches (5-7.5 cm) per year from age 2 until puberty. During puberty, growth accelerates to 3-4 inches per year for girls and 4+ inches per year for boys during peak growth. Growth less than 2 inches per year before puberty may warrant medical evaluation.
The mid-parental height formula has a margin of error of about ±4 inches (10 cm). It's most accurate for children of average-height parents and less accurate when parents are unusually tall or short, as children tend to 'regress toward the mean.' It's a good starting estimate but not a clinical diagnosis.
The Khamis-Roche method is a height prediction formula developed in 1994 that uses a child's current height, weight, and parents' heights to predict adult stature without requiring bone age X-rays. It's the most accurate non-clinical prediction method with an error margin of ±2.1 inches for boys and ±1.7 inches for girls.
The average height for a 14-year-old boy is about 5 feet 4 inches (164 cm), and for a 14-year-old girl about 5 feet 3 inches (160 cm). This is the age where boys typically begin catching up to and surpassing girls in height.
Yes, significantly. While genetics determines 60-80% of height, nutrition is the most important environmental factor for the remaining 20-40%. Adequate protein, calcium, vitamin D, and overall calories during childhood and adolescence are essential for reaching full height potential. Malnutrition during growth years can permanently reduce adult height.
Yes, identical twins can differ in height by up to 1-2 inches despite sharing the same DNA. This happens because environmental factors like nutrition, illness, and physical activity during growth years create small differences. It demonstrates that even with identical genetics, height isn't 100% predetermined.