estimate your child's adult height from parents' heights
Using the height calculator
Age & current height enable a second, informal estimate (see below) — useful mainly around age 2 for boys or 18 months for girls.
Mid-Parental Height Estimate
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How to predict a child's adult height
The height calculator here uses the mid-parental height method (also called the "target height" method) — the most widely cited approach for estimating a child's eventual adult height from their parents' heights. It's simple, requires no measurements of the child at all, and has been used in pediatric practice for decades.
Add the two parents' heights together (converted to the same unit).
For a boy: add 13 cm (about 5 in), then divide by 2.
For a girl: subtract 13 cm (about 5 in), then divide by 2.
The result is the target height — the center of the likely adult height range.
A margin of roughly ±10 cm (4 in) is applied around that target, reflecting the natural variation this method doesn't capture (genetics beyond parents, nutrition, health).
How accurate is this height predictor?
Mid-parental height is a reasonable starting estimate, not a precise forecast. Height is highly heritable (studies estimate 60–80% of adult height is explained by genetics), but a single child's final height still commonly lands anywhere within about 10 cm (4 in) of this estimate in either direction. It also assumes the child grows up with adequate nutrition and no health conditions that affect growth — if either of those isn't the case, actual height can diverge more.
It also works better as an average across many children than as a guarantee for any one child — genetics alone doesn't set a fixed number, it sets a likely range.
Other methods for predicting height
Mid-Parental Height (used above)
Based only on parents' heights and the child's sex. Simple, fast, and doesn't require measuring the child at all.
Bone age / growth chart methods
Pediatricians can use a child's current height, weight, age, and sometimes an X-ray-based "bone age" against standardized growth curves for a more individualized estimate. These require clinical measurement and interpretation, so they aren't available in a simple online calculator.
Percentile tracking
Most children track along a fairly consistent percentile line on a growth chart through childhood. A doctor plotting several measurements over time can often estimate an adult height range by extending that line — more accurate than a single mid-parental calculation, but it requires ongoing measurements.
Want to check your own current numbers instead of predicting a child's future height? Try the BMI Calculator.
Factors affecting height
A child's eventual height is shaped by more than genetics alone. The main contributors:
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Genetics
The single biggest factor — parents' heights strongly predict a child's likely range, though not an exact number.
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Nutrition
Inadequate protein, calories, or key micronutrients during childhood can measurably slow growth and limit final height.
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Sleep & hormones
Growth hormone is released primarily during deep sleep — consistent, adequate sleep supports normal growth patterns.
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Physical activity
Regular activity supports healthy bone and muscle development, complementing (not replacing) good nutrition.
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Chronic illness
Some chronic conditions and hormone disorders can affect growth — a doctor should evaluate any child growing notably slower than peers.
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Environment
Access to healthcare, consistent nutrition, and a stable environment in early childhood all measurably influence growth outcomes.
Nutrients required for healthy growth
Height growth is fueled by specific nutrients working together — no single "magic" nutrient does it alone.
Nutrient
Why it matters
Good sources
Protein
Builds and repairs the tissue that makes up bone, muscle, and cartilage
Meat, fish, eggs, dairy, legumes, tofu
Calcium
Core mineral for bone density and length
Dairy, fortified plant milks, leafy greens, tofu
Vitamin D
Needed for the body to actually absorb and use calcium
Sunlight, fatty fish, fortified milk/cereal, eggs
Zinc
Supports cell growth and division, including in growth plates
Meat, shellfish, beans, nuts, seeds, dairy
Vitamin A
Supports bone growth and cell development
Carrots, sweet potatoes, spinach, eggs, dairy
Iron
Supports oxygen delivery for growing tissue; deficiency can slow growth
Red meat, poultry, beans, spinach, fortified grains
Iodine
Needed for thyroid hormone, which regulates growth
Iodized salt, dairy, seafood, eggs
Omega-3s
Supports overall development, including bone health
Fatty fish, walnuts, flaxseed, chia seeds
Foods that support healthy growth
Dairy & eggs
Calcium, protein, vitamin D, and B12 in one package — milk, yogurt, cheese, and eggs are foundational for growing children.
Lean meats & fish
High-quality protein, iron, zinc, and (in fatty fish) omega-3s and vitamin D.
Leafy greens & vegetables
Calcium, vitamin A, vitamin K, and folate — spinach, kale, and broccoli are standouts.
Legumes & nuts
Plant protein, zinc, iron, and healthy fats — beans, lentils, almonds, and walnuts.
Fruits
Vitamin C (helps collagen formation for bone and cartilage) plus fiber and antioxidants.
Whole grains
Steady energy for growth, plus B vitamins, iron, and fiber — oats, brown rice, whole wheat.
Want to check whether a child or teen's diet is actually hitting these targets? Log meals in the Calorie Tracker to see protein and micronutrient-relevant totals.
Average adult height (United States)
Average adult male height~5'9" (175 cm)
Average adult female height~5'4" (162 cm)
These are broad population averages (commonly cited from U.S. national health survey data) — individual height varies widely around them, shaped by all the genetic and environmental factors above.
Not medical advice: This calculator gives a rough, population-based estimate only. If you're concerned about a child's growth rate — whether notably fast, slow, or off their typical percentile line — a pediatrician can plot accurate growth charts and check for underlying causes.
Estimates use the mid-parental height method, a general population-based formula. Individual results vary; this is not medical advice or a diagnostic tool.