Adult Height Calculator

Wondering how tall you or your child will be as an adult? This calculator provides a family-based estimate of expected adult height using the biological parents' stature. It is designed for estimating future height in children and teenagers — not for measuring or converting an adult's current height. The result is an informed approximation, not a guaranteed outcome.

How to Use the Adult Height Calculator

This calculator focuses on predicting adult height from genetic data. Follow these steps:

1. Select biological sex — Choose male or female. The formula applies a different adjustment for each sex.
2. Enter the mother's height — Provide the biological mother's height in centimeters. Convert feet and inches to centimeters before entering the value if needed.
3. Enter the father's height — Provide the biological father's height in centimeters.
4. Click "Calculate Height" — The result displays an estimated adult-height target and a typical range of about ±5 cm.

This tool does not require the child's current age or measurements. Age-aware estimation methods use a child's present height and age as additional inputs.

How Predicted Adult Height Is Calculated

The calculator uses the mid-parental height method, a widely used genetic benchmark in pediatric practice. The formula averages both parents' heights and adjusts for the child's sex:

• For males: (Mother's height + Father's height) ÷ 2 + 6.5 cm
• For females: (Mother's height + Father's height) ÷ 2 − 6.5 cm

The 6.5 cm (approximately 2.5 inches) adjustment reflects the average height difference between adult men and women. The result represents a genetic target height — the point around which a child's adult height is statistically most likely to fall, given their parents' stature.

A ±5 cm range around this target captures most expected outcomes. However, because the formula only considers parental height and sex, it cannot account for individual variations in growth pattern, health, or puberty timing.

Adult Height Prediction Methods Explained

Several methods exist for predicting adult height, ranging from simple formulas to clinical assessments. Here is how the most common approaches compare:

Mid-parental height method

The approach used by this calculator. It requires only the parents' heights and the child's sex. Advantages: simple, can be used at any age including before birth. Disadvantage: does not use the child's own growth data, so precision is limited.

Bone-age assessment (Greulich-Pyle method)

A pediatrician or radiologist takes an X-ray of the child's left wrist and compares the bone maturity to reference standards. This reveals how much growth potential remains. It is one of the most accurate clinical methods but requires an in-person medical visit.

Khamis-Roche method

A formula-based approach that combines the child's current age, height, weight, and both parents' heights. It does not require an X-ray and is considered more accurate than the mid-parental method alone for children aged 4 and older. You can use our interactive Height Calculator on the homepage to calculate predictions using this method.

Bayley-Pinneau method

Uses bone-age data in combination with current height to project adult stature. Typically used in clinical settings when bone-age X-rays are already available.

For everyday parental use, the mid-parental method offers a practical balance of simplicity and usefulness. For children whose growth raises specific concerns, a pediatric endocrinologist may combine several methods for a comprehensive assessment.

When Do Children and Teenagers Reach Their Adult Height?

The age at which growth stops varies by sex and individual puberty timing:

• Girls — Most girls reach approximately 95% of their adult height by age 13 and complete growth between ages 14 and 16. Growth after menarche (first period) is typically limited to 5–7 cm.
• Boys — Boys generally complete the majority of their growth between ages 16 and 18. Peak growth velocity occurs around ages 13–14, later than in girls. Some boys with late-onset puberty may continue growing into age 19 or 20.

Growth plate closure is the biological event that ends linear bone growth. The growth plates (epiphyseal plates) are areas of cartilage near the ends of long bones. During childhood and adolescence, these plates allow bones to lengthen. As sex hormones increase during puberty, the cartilage gradually calcifies and the plates fuse, permanently ending height gain.

The timing of this closure is influenced by genetics, hormonal levels, and overall health. A bone-age X-ray is the only way to definitively assess whether growth plates are still open.

Factors That Can Influence Final Adult Height

While the genetic blueprint (represented by the mid-parental target) sets the primary expectation, several environmental and biological factors determine whether a person reaches, exceeds, or falls short of that target:

• Nutrition during growth years — Adequate protein, calories, calcium, and micronutrients are essential. Populations with improved nutrition over generations have shown measurable increases in average adult height (the secular trend).
• Hormonal health — Growth hormone, thyroid hormones, insulin-like growth factor 1 (IGF-1), and sex hormones all regulate bone growth. Deficiencies or excesses in any of these can alter adult height.
• Chronic illness — Conditions such as celiac disease, inflammatory bowel disease, chronic kidney disease, or congenital heart disease can impair growth if poorly managed. Treatment of the underlying condition often allows partial or full catch-up growth.
• Sleep — Growth hormone secretion peaks during deep sleep. Children and adolescents who routinely get insufficient sleep may not optimize their growth hormone release.
• Medications — Long-term use of certain medications, such as high-dose corticosteroids, can suppress growth in children. Growth hormone therapy, when medically indicated, can increase adult height in children with documented deficiency.

It is important to understand that no supplement, stretching regimen, or exercise program can increase adult height beyond a person's genetic potential. Claims to the contrary are not supported by credible medical evidence.

How to Interpret Your Predicted Adult Height Result

The calculator produces an estimate and a range. Here is what each part conveys:

• Estimated adult height — The single most probable value based on the formula. For example, "174.5 cm" represents the statistical midpoint for a child with these parental heights.
• Genetic target range — The band of about ±5 cm (for example, 169.5–179.5 cm) within which the majority of children with similar parental heights would be expected to fall.

Important distinctions to keep in mind:

• An estimated adult height is a probability-based projection, not a promise.
• A likely height range expresses confidence — most outcomes fall within it, but some do not.
• A person's actual final height is only known once growth is complete and confirmed by growth plate closure.

If you are a teenager wondering about your own growth, remember that this tool estimates where genetics point — your actual trajectory depends on when you entered puberty, your nutrition, your health, and many other personal factors. A visit to your healthcare provider can give you more individualized information.