Height Calculator UK | Predict Adult Height 2025

The mid-parental height formula has a margin of error of approximately ±10 cm (about 4 inches). It estimates the genetic midpoint of height potential — the actual range within which 95% of children will fall is ±10 cm around this value. Around 80% of height variation is genetic, but nutrition, sleep, health, and other environmental factors determine whether a child reaches their genetic ceiling.

The average height for adult men in the UK is approximately 175.3 cm (5 feet 9 inches), and for adult women approximately 161.9 cm (5 feet 4 inches), based on the Health Survey for England. Heights increased significantly through the 20th century due to improved nutrition and living standards, but have largely stabilised in recent decades. UK men and women are taller on average than global means but shorter than some Northern European populations.

Girls typically stop growing in height between ages 14 and 16, usually 2–3 years after the start of their menstrual cycle. Boys generally continue growing until ages 17–19, with some continuing slowly into their early 20s. Growth ends when growth plates (epiphyseal plates) in the long bones fuse under the influence of oestrogen and testosterone. A bone age X-ray can estimate remaining growth potential.

While genetics accounts for roughly 80% of height variation, nutrition (protein, calcium, vitamin D, zinc) is critical during growth years. Sleep supports growth hormone release. Moderate physical activity promotes healthy bone development. Chronic illness — particularly coeliac disease, Crohn's, kidney disease, or conditions requiring long-term steroids — can significantly impair growth. Hormonal conditions such as growth hormone deficiency or hypothyroidism are treatable causes of short stature.

Growth plates (epiphyseal plates) are areas of cartilage near the ends of long bones where new bone is produced, increasing length. They are present throughout childhood and adolescence. Because they are softer than mature bone, they are vulnerable to fracture (Salter-Harris fractures) in children. Once puberty is complete, sex hormones cause growth plates to fuse and harden, ending height gain. A bone age X-ray of the wrist assesses plate status and remaining growth potential.

Yes, significantly. Adequate nutrition is essential for reaching genetic height potential. Protein provides building blocks for bone and tissue. Calcium and vitamin D are critical for bone mineralisation. Zinc deficiency is associated with growth retardation. Conversely, childhood obesity can cause earlier puberty, which may lead to earlier growth plate closure and a shorter final adult height. A balanced diet following the NHS Eatwell Guide, with sufficient calories and micronutrients, supports optimal growth.

You can optimise the environmental factors that support a child reaching their genetic height potential. Ensure adequate nutrition (protein, calcium, vitamin D), consistent sleep (9–11 hours for primary school children, 8–10 for teenagers), regular physical activity, and prompt treatment of any illnesses. You cannot change genetic potential, but these factors determine how close to the genetic ceiling a child reaches. Avoid unregulated supplements marketed for "height growth" — these lack evidence and some may be harmful.