Height Calculator
Convert height between feet and inches, centimetres, and metres instantly.
Predict adult height for children, estimate based on parental heights, or convert between cm and ft/in.
Estimates an adult height based on the child's current age, height, and parental heights using the mid-parental height method with current growth trajectory.
Estimate a child's adult height from parental heights alone using the mid-parental height formula.
Instantly convert between centimetres and feet & inches. Edit either field to update the other.
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How to Predict Adult Height from a Child's Current Height
Genetics & Environment
Genetics account for roughly 60–80% of adult height. The remainder is influenced by nutrition, sleep quality, physical activity, and general health during childhood and adolescence.
Mid-Parental Height Method
This formula averages parental heights and adds or subtracts a sex adjustment (±6.5 cm). It predicts a child's adult height with a typical error of about ±5–8 cm (2–3 inches).
Growth Trajectory
A child's current height relative to peers (their CDC percentile) provides information about their growth trajectory that, combined with parental height, gives a better prediction than genetics alone.
Accuracy & Limitations
No formula can perfectly predict adult height. Predictions are estimates with real uncertainty — the actual result can differ by several centimetres. For medical concerns, consult a paediatrician. To use your height in a BMI calculation, try the BMI calculator.
Worked example
Boy aged 10, current height 4 ft 5 in (134 cm). Father 5 ft 11 in (180 cm), mother 5 ft 5 in (165 cm). Mid-parental height for a boy = ((180 + 165) ÷ 2) + 6.5 = 179 cm (5 ft 10 in). Including the child's current growth percentile, the predicted adult range is approximately 5 ft 8 in–5 ft 11 in.
Related calculations
To convert a weight as well, use the weight converter. Both feed the BMI calculator, which needs height and weight in matching units.
Frequently Asked Questions
How accurate is a child height prediction calculator?
Height prediction formulas based on parental heights have a typical error of ±5–8 cm (2–3 inches). They provide a statistical estimate based on genetic potential — actual adult height also depends on nutrition, sleep, illness, and other environmental factors during childhood. For medical concerns, consult a paediatrician.
What is the mid-parental height method?
The mid-parental height formula estimates adult height by averaging the parents' heights and adding 6.5 cm for boys or subtracting 6.5 cm for girls. It represents the midpoint of genetic potential. Including the child's current height and growth percentile alongside this method improves prediction accuracy.
At what age do people stop growing?
Most girls reach final adult height by age 15–17, shortly after puberty. Most boys continue growing until age 17–19. Growth plates (epiphyseal plates) close at the end of puberty, after which height cannot increase naturally. Some individuals continue growing into their early 20s, particularly boys with delayed puberty.
How do I convert height from feet and inches to centimetres?
Multiply total inches by 2.54. First convert feet to inches (1 foot = 12 inches), then add the remaining inches. For example: 5 ft 9 in = (5×12 + 9) = 69 inches × 2.54 = 175.3 cm. The height converter in this calculator handles this automatically in both directions. For other unit conversions, try the unit converter.
Evidence & Methodology
How This Page Is Grounded
Method
Converts height using exact defined relationships between metres, centimetres, inches and feet.
Important limitation: Displayed values are rounded to the precision shown; repeated conversion of rounded values can introduce small differences.
Primary Sources
- The International System of Units (SI Brochure) International Bureau of Weights and Measures
- SI units National Institute of Standards and Technology
Quality Checks
Exact factors and round-trip conversions are checked at common and boundary values.
See how sources are selected and corrections are handled in our Editorial & Calculation Methodology, and which automated checks this page has to pass in How We Test.