Baby Height Predictor
How Tall Will My Child Be?
Predict your child's likely adult height from both parents' heights using the mid-parental height method and Khamis-Roche formula. Results in cm and feet/inches with a height range. Instant, free, private.
| Average Adult Height | Male | Female |
|---|---|---|
| Global Average | 171 cm (5ft 7in) | 159 cm (5ft 3in) |
| UK Average | 175.3 cm (5ft 9in) | 161.9 cm (5ft 4in) |
| US Average | 175.4 cm (5ft 9in) | 161.7 cm (5ft 4in) |
| Pakistan Average | 166.9 cm (5ft 6in) | 154.2 cm (5ft 1in) |
| India Average | 164.9 cm (5ft 5in) | 152.6 cm (5ft 0in) |
Source: NCD Risk Factor Collaboration. Averages vary by region, ethnicity, and birth cohort.
How Is Child Height Predicted?
Height prediction tools are most useful for understanding the genetic range your child is likely to fall within, setting realistic expectations, and identifying potential growth concerns early when a child is tracking significantly below their predicted range. For detailed growth monitoring, always use official CDC or WHO growth charts in combination with regular pediatric check-ups. Use our Baby Weight Percentile Calculator alongside this tool to track your child's full growth trajectory.
The Mid-Parental Height Formula Explained
The mid-parental height (MPH) formula is the most widely used clinical method for predicting a child's adult height. It was developed from the observation that children's heights tend to cluster around a value halfway between both parents' heights, adjusted for the approximately 13cm average height difference between adult males and females:
- For boys: (Father's height in cm + Mother's height in cm + 13) / 2
- For girls: (Father's height in cm + Mother's height in cm - 13) / 2
The result is the mid-parental target height. The expected range in which 95% of children with those parent heights will fall is the mid-parental height plus or minus 8.5cm (approximately 3.5 inches). A child tracking significantly outside this range -- more than 2 standard deviations from the MPH -- is generally worth discussing with a pediatrician to rule out growth hormone deficiency or other growth concerns.
An important statistical concept related to this formula is regression to the mean: very tall parents tend to have children who are tall but slightly shorter than themselves, and very short parents tend to have children who are short but slightly taller. This is a natural statistical phenomenon and not a sign of any problem. Check your child's weight alongside height with our Baby Weight Percentile Calculator.
The Khamis-Roche Method
The Khamis-Roche method is a more precise height prediction approach for children who are already born and have measurable current height and weight. It uses four inputs: the child's current age, current height, current weight, and both parents' heights. It was developed from the Fels Longitudinal Study, one of the largest long-term child growth studies conducted in the US.
The Khamis-Roche method is considered more accurate than the simple mid-parental formula for children aged 4-17 because it accounts for the child's current growth trajectory alongside genetic potential. This calculator uses the mid-parental method (which works before birth and at any age) as its primary formula since it requires only parents' heights. If your child is already several years old, a pediatrician can apply the Khamis-Roche method using growth chart data.
How Much Is Height Genetic?
Height is one of the most heritable human traits. Research consistently estimates that genetics accounts for 60-80% of the variation in adult height between individuals in populations with adequate nutrition. Twin studies are particularly informative -- identical twins raised apart show remarkably similar heights, while fraternal twins show more variation, confirming the dominant role of genetics.
Mom or Dad -- Who Matters More?
Both parents contribute roughly equally through dozens of height-associated genes spread across multiple chromosomes. Some studies suggest the father's contribution may have a slightly stronger influence on daughter's height and the mother's on son's height, but this effect is small. The mid-parental formula treats both equally, which is the most practical and evidence-supported approach.
Regression to the Mean
Very tall parents tend to have children who are tall but typically somewhat shorter than themselves. Very short parents tend to have children who are short but often somewhat taller. This phenomenon -- regression to the mean -- is a statistical reality across all heritable traits and is built into the mid-parental height formula's correction factor.
The remaining 20-40% of height variation is explained by non-genetic factors, primarily nutrition, general health, sleep quality, and to a lesser extent, physical activity. Understanding your child's genetic height potential helps contextualize whether a shorter-than-average stature reflects genetics or a potentially addressable factor like nutritional deficiency. Check our Calcium Calculator and Vitamin D Calculator to ensure your child is getting adequate nutrients for their genetic height potential.
What Affects a Child's Growth Beyond Genetics?
- Nutrition: The most modifiable factor. Chronic malnutrition or specific nutrient deficiencies (calcium, Vitamin D, zinc, protein, iron) can prevent a child from reaching their genetic height potential. Well-nourished children reach their genetic potential; poorly nourished children may not
- Sleep: Growth hormone is released in pulses during deep sleep, primarily in the first few hours after falling asleep. Children who consistently get inadequate sleep have lower average growth hormone levels. School-age children need 9-11 hours of sleep for healthy development
- Chronic illness: Conditions that affect nutrient absorption (coeliac disease, inflammatory bowel disease), hormone function (thyroid disorders, growth hormone deficiency), or overall health can significantly affect growth. Children with unexplained growth faltering should be evaluated by a pediatrician
- Physical activity: Regular weight-bearing exercise stimulates bone formation and growth plate activity. Children who are physically active tend to have better bone density and may support their height development, though the effect on final height is modest
- Socioeconomic factors: Access to nutritious food, healthcare, clean water, and safe environments all affect growth outcomes at the population level. Countries with better nutrition and healthcare consistently see taller average adult heights than those without
- Stress and emotional environment: Severe chronic psychological stress, including stress-related to adverse childhood experiences, can suppress growth hormone secretion and affect linear growth
Nutrition for Maximum Height Potential
While genetics sets the ceiling, nutrition determines how close a child gets to that ceiling. The key nutrients for growth are:
- Calcium: 700-1300mg per day depending on age (check our Calcium Calculator). Essential for bone matrix formation. Best sources: dairy, fortified plant milks, leafy greens, sesame seeds, tofu
- Vitamin D: 600 IU daily. Without adequate Vitamin D, calcium cannot be properly absorbed into bones. Best sources: sunlight exposure, fortified dairy, fatty fish (check our Vitamin D Calculator)
- Protein: 0.85-1.2g per kg bodyweight daily (check our Protein Calculator). Essential for growth hormone signaling and all tissue building. Best sources: meat, fish, eggs, dairy, lentils, chickpeas
- Zinc: 3-11mg per day by age. Critical for growth factor signaling and cell division. Best sources: meat, shellfish, legumes, nuts, seeds, wholegrains
- Iron: 7-15mg per day by age. Required for oxygen transport to rapidly growing tissues and for normal growth hormone metabolism. Best sources: red meat, lentils, spinach, fortified cereals (check our Iron Calculator)
- Overall caloric adequacy: Children who are chronically undernourished -- even without specific deficiencies -- will not grow to their genetic potential. Regular balanced meals throughout the day are essential
When Do Children Stop Growing?
Growth in height stops when the growth plates (epiphyseal plates) at the ends of long bones fuse, which happens at different times for boys and girls:
- Girls: Typically stop growing in height around age 14-16, usually 2-3 years after their first period. The pubertal growth spurt in girls typically occurs earlier (around age 10-13) and is shorter in duration than boys
- Boys: Typically stop growing around age 16-18, after puberty is complete. Boys' pubertal growth spurt occurs later (around age 12-15) but tends to be more prolonged and intense, contributing to the average height difference between adult males and females
- Some individuals may continue to grow slightly until their early 20s, though this is uncommon for significant height gains after age 18
If you are tracking your daughter's growth alongside her cycle, use our Period Calculator to understand her cycle and Ovulation Calculator as she reaches reproductive age. Monitor newborn and infant growth with our Baby Weight Percentile Calculator.
