Height Calculator (Adult Height Predictor)

ft
in
ft
in

Prediction Methods

Mid-Parental Height

Simple formula using parents' heights only.

Boys: (Mom + Dad + 5") / 2

Girls: (Mom + Dad - 5") / 2

Khamis-Roche

More accurate method that also considers child's current height, weight, and age. Best for children ages 4-17.

Average Adult Heights

US Men (average)5'9" (175 cm)
US Women (average)5'4" (162 cm)
Growth complete (boys)~16-18 years
Growth complete (girls)~14-16 years

Understanding Height Prediction

Height prediction uses genetic and developmental factors to estimate a child's adult height. While genetics account for about 60-80% of height variation, environmental factors like nutrition, health, and physical activity also play significant roles.

Factors Affecting Height

  • Genetics: The biggest factor - tall parents tend to have tall children
  • Nutrition: Adequate protein, vitamins, and minerals are essential for growth
  • Sleep: Growth hormone is primarily released during sleep
  • Physical activity: Exercise stimulates growth hormone release
  • Health: Chronic illness can affect growth
  • Hormones: Growth hormone and thyroid function impact height

Growth Patterns

Boys

  • Growth spurt: ages 12-16
  • Peak growth: ~14 years old
  • Stop growing: 16-18 years
  • May grow until early 20s

Girls

  • Growth spurt: ages 10-14
  • Peak growth: ~12 years old
  • Stop growing: 14-16 years
  • Usually complete by 18

When to See a Doctor

Consider consulting a pediatrician if your child:

  • Is significantly shorter than peers (below 3rd percentile)
  • Has stopped growing or growth has slowed dramatically
  • Shows signs of early or delayed puberty
  • Has a predicted height very different from genetic potential

Important Note

These calculations provide estimates only. Actual adult height can vary significantly from predictions. The margin of error is typically around 2-4 inches (5-10 cm). For accurate growth assessment, consult a pediatrician who can use bone age X-rays and growth charts.

Frequently Asked Questions

How accurate are height prediction calculators?

Height prediction calculators typically have a margin of error of 2-4 inches (5-10 cm). The Mid-Parental Height method provides a rough estimate, while the Khamis-Roche method, which factors in the child's current measurements, is generally more accurate. For the most precise predictions, pediatricians use bone age X-rays combined with growth charts.

What factors influence a child's final adult height?

Adult height is determined by genetics (60-80%), nutrition, overall health, sleep quality, physical activity, and hormonal factors. While genetics set the potential range, environmental factors determine where within that range a child ends up. Chronic illness, malnutrition, or hormonal imbalances can impact growth negatively.

At what age do children stop growing?

Girls typically stop growing between ages 14-16, usually about 2 years after their first menstrual period. Boys continue growing until ages 16-18, sometimes into their early 20s. Growth plates (epiphyseal plates) in bones close when puberty ends, marking the end of height increase.

Can children grow taller than both parents?

Yes, children can be taller than both parents due to genetic variation and improved nutrition. Height is determined by multiple genes from both parents, and children can inherit a favorable combination. Additionally, better nutrition and healthcare in modern times often lead to children surpassing parental heights.