Average Height Comparison Calculator

How This Calculator Works

Average height varies by age and gender — this calculator compares your own height against the reference average for people your age and gender. Enter your gender at birth, age, and height, and it reports how many centimeters (or inches) above or below average you are.

This calculator draws from three separate, age- and country-appropriate reference sources, not one table stretched across every age and every visitor:

• Ages 20 and up, when your Country setting (in Settings) is the United States or one of its territories: the CDC’s National Center for Health Statistics (NCHS) “Anthropometric Reference Data for Children and Adults: United States, August 2021–August 2023” report — part of NHANES, a nationally representative survey that physically measures a sample of the U.S. population rather than relying on self-reported height. This calculator uses that report’s own age-band breakdown (20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80 and older) for adults, separately for men and women.
• Ages 20 and up, everywhere else: a single worldwide average height per gender — 171 cm for men, 159 cm for women — commonly cited from the 2016 NCD-RisC (“NCD Risk Factor Collaboration”) pooled analysis published in eLife, “A century of trends in adult human height.” This figure isn’t broken out by age band the way the U.S. table above is, since no equivalent age-banded worldwide dataset has actually been published — showing one flat, honestly-labeled worldwide figure is more accurate than inventing age-specific global numbers.
• Ages 2 through 19, regardless of country: the World Health Organization’s median height-for-age reference — the WHO Child Growth Standards (2006) for ages 2-5 and the WHO Growth Reference for School-Aged Children and Adolescents (2007) for ages 6-19. This is the same international reference the CDC itself directs U.S. clinicians to use for children under 2, and the one pediatricians worldwide use to track growth through adolescence — a genuinely different, age-appropriate methodology from either adult figure above, not an extension of them. This reference is already worldwide, so it doesn’t change based on your Country setting.

The calculator never blends or interpolates between these three sources — it simply looks up whichever one actually applies to the age (and, for adults, the country) you’ve specified, and always states which one it used. Changing your Country setting immediately updates the result.

The Formula

$$\text{Difference} = \vA{\text{Your Height}} - \vB{\text{Age/Gender/Country Reference Average}}$$

The reference average is looked up directly from whichever cited table applies — the U.S. CDC table for adults whose Country is the United States or one of its territories, the flat worldwide NCD-RisC-sourced average for adults everywhere else, or the WHO reference for ages 2-19 regardless of country — then subtracted from your entered height. The result is also shown as a percentage of the average.

This calculator deliberately does not compute a percentile (e.g. “taller than 80% of people your age”). A real percentile needs to know how spread out heights are around the average — the standard deviation — and neither cited source’s public summary tables include that figure broken out by age and gender the way this calculator uses them. Inventing one would produce a falsely-precise-looking number, so this stays a plain comparison against the average instead.

Worked Examples

A 25-year-old man who is 180 cm tall:

1. The 20-29 male average is 176.3 cm (69.4 inches, per the CDC table).
2. Difference: $180 - 176.3 = +3.7$ cm — about 2.1% taller than average for his age and gender.

An 8-year-old boy who is 130 cm tall:

1. The WHO median for an 8-year-old boy is 127.3 cm.
2. Difference: $130 - 127.3 = +2.7$ cm — a bit taller than average for his age and gender.

Common Mistakes

• Comparing against the overall adult average instead of your own age band. The CDC data shows average height differs by age band — this calculator matches you to your own band rather than one flat national number, since the two can differ by an inch or more.
• Reading this as a percentile or ranking. “3.7 cm above average” doesn’t translate directly into “taller than X% of people” without knowing how spread out heights are — see above.
• Mixing up the three data sources. A child/teen result (ages 2-19) is always compared against the international WHO growth reference; an adult result (20+) is compared against either the U.S.-specific CDC/NHANES survey or a flat worldwide average, depending on your Country setting — three different, non-interchangeable datasets. The calculator’s own “Notes” section always states which one applies to your result.
• Expecting an age-banded breakdown for the worldwide adult average. Unlike the U.S. table (which breaks adults into 20-29, 30-39, etc.), the worldwide adult figure is a single flat average for all ages 20 and up, since no equivalent age-banded worldwide dataset has actually been published.