Child height predictor
Estimate how tall your child may grow from both parents' heights. Add your toddler's current height (from 18 months) to refine it with their own growth percentile.
Child's height works from 18 months to 5 years.
- Mid-parental height
- 5′ 5″
- Average adult woman (US)
- 5′ 4″
How the prediction works
Mid-parental height (Tanner, 1970) averages the parents' heights after adjusting for the roughly 13 cm average difference between men and women. About 95% of children end up within 8.5 cm of it.
Percentile tracking: after about age 2, children tend to stay near the same height percentile until puberty. We take your child's WHO height-for-age z-score and map it onto the adult height distribution from the CDC's NHANES survey. When you provide both, the calculator averages the two methods.
Puberty timing, nutrition and health all shift the final result, so treat this as a curiosity rather than a forecast. Current height percentile: baby height percentile calculator.
Frequently asked questions
How accurate is a child height predictor?
Not very precise. The mid-parental method predicts adult height within about ±8.5 cm (3.3 in) for roughly 95% of children. Combining it with the child's own height percentile after age 2 narrows it slightly. The most accurate clinical methods need a bone-age X-ray.
Is it true you can double a 2-year-old's height?
It's a rough rule of thumb: boys reach about half their adult height around age 2, girls around 18 months. It tends to be within a few inches, but it ignores genetics and timing of puberty.
What is mid-parental height?
The average of the parents' heights, adjusted for sex: add 13 cm (5 in) to the mother's height for a boy, or subtract 13 cm from the father's height for a girl, then average with the other parent. Paediatricians use it to judge whether a child's growth fits their family.