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Calculator · Tanner target height

Mid-parental height calculator

Mother's height
ftin
Father's height
ftin

Your result

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Shown as a 90% range: the adult height lands inside it 9 times out of 10. Heights and weight are never sent anywhere.

Short answer

Mid-parental height = (mother's height + father's height) ÷ 2, then +6.5 cm (2.5 in) for a son or −6.5 cm for a daughter. The child's target range is that number ±8.5 cm (about 3.3 in). It needs only the parents' heights, so it works at any age, including for babies.

Reviewed · 3 sources · Not medical advice

Worked example

Mother 165 cm, father 180 cm.

SonDaughter
Parents' average172.5 cm172.5 cm
Sex adjustment+6.5 cm−6.5 cm
Target height179 cm (5′10½″)166 cm (5′5″)
Target range170.5–187.5 cm157.5–174.5 cm

Mid-parental vs. Khamis-Roche

Mid-parental height, introduced by Tanner and colleagues in 1970, answers "what height fits this family?". Khamis-Roche answers "where is this child heading?" by adding the child's own age, height and weight. For a child aged 4 to 17½, Khamis-Roche is the better predictor. Below 4, or when you only know the parents, mid-parental is the standard.

Questions people ask

What is the mid-parental height formula?

Boys: (father + mother + 13 cm) ÷ 2. Girls: (father + mother − 13 cm) ÷ 2. In inches, use 5 in instead of 13 cm. The 13 cm is the average height difference between adult men and women.

How accurate is mid-parental height?

It is a rough guide. The ±8.5 cm target range is wide because it ignores the child's own growth so far. If your child is 4 or older, the Khamis-Roche calculator uses their height and weight too and narrows the range to about ±5 cm.

Why do doctors use mid-parental height?

To check whether a child's growth fits the family. A child tracking well below the target range on the growth chart may need a closer look; one tracking within it is usually just following their genes.

Does mid-parental height work for adopted children?

No. It depends on the biological parents' heights. Without them, a doctor would use the child's own growth pattern and bone age instead.

Sources

  1. Tanner JM, Goldstein H, Whitehouse RH. Standards for children's height at ages 2–9 years allowing for height of parents. Arch Dis Child 1970;45:755–762
  2. Khamis HJ, Roche AF. Predicting adult stature without using skeletal age: the Khamis-Roche method. Pediatrics 1994;94(4):504–507 (erratum 1995;95:457)
  3. CDC. Growth charts (2000 stature-for-age, ages 2 to 20)

Your exact number and a daily plan

TallPath runs the same prediction from a 2-minute quiz, shows where you'll likely land inside the range, and builds a daily sleep, food and posture plan around it.

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