Height Percentile Calculator
Enter your height, sex, and age group to find where you rank among US adults. The calculator uses CDC NHANES reference data and returns your exact percentile, z-score, and a plain-English interpretation of how your height compares to the population. Switch freely between metric (centimetres) and imperial (feet and inches); results update instantly. This tool is for educational purposes; consult a healthcare provider for medical height assessments.
How your height percentile is calculated
The calculator compares your height to a statistical model of the US adult population derived from the CDC National Health and Nutrition Examination Survey (NHANES). Heights in the adult population follow an approximately normal (bell-shaped) distribution, so the percentile is found using the cumulative distribution function (CDF) of the normal distribution.
The formula has two steps. First, your height is converted to a z-score:z = (your height - population mean) / standard deviation
Then the z-score is passed through the standard-normal CDF to yield the percentile:percentile = 100 x P(Z <= z) = 100 x 0.5 x (1 + erf(z / sqrt(2)))
For example, a man aged 25 who is 6 ft tall (183 cm) has z = (183 - 176.1) / 7.40 = 0.93, giving a percentile of about 82. That means he is taller than roughly 82 % of US men in his age group.
Average US height by sex and age group
Average adult height in the United States has been remarkably stable over recent decades. According to NHANES 2017-2020 data, adult men average 175.3 cm (5 ft 9 in) and adult women average 161.5 cm (5 ft 4 in) across all ages over 20.
Height does decline gradually with age in older adults due to spinal compression and vertebral changes. Men in their 20s average about 176.1 cm, falling to roughly 169.8 cm by age 80+. Women show a similar pattern, declining from 162.4 cm in their 20s to about 157.2 cm at 80+. Using age-matched comparisons (available in the "Age group" dropdown) therefore gives a fairer picture than comparing against the overall adult average.
The standard deviation for both sexes is approximately 7 cm (about 2.8 inches), meaning that roughly two-thirds of adults fall within 7 cm of the mean, and 95 % fall within 14 cm.
What your z-score and percentile tell you
A percentile of 50 means exactly average: half the reference group is shorter, half is taller. Percentiles above 75 are above average; below 25 are below average. The 3rd and 97th percentiles are conventional clinical boundaries often used in growth charts to flag unusually short or tall stature in children and adolescents, though in healthy adults these are simply descriptive labels, not medical thresholds.
The z-score (standard deviation score) carries the same information in a different scale. A z of +1 means one standard deviation above the mean, putting you at roughly the 84th percentile. A z of -2 corresponds to about the 2nd percentile. Z-scores are often used in clinical and research settings because they do not depend on knowing the percentile table.
Limitations and what height percentile does not tell you
Several important caveats apply to this calculator:
- US adults only. The reference data come from NHANES, which surveys the US civilian non-institutionalised population. Average heights differ by country - the Dutch are among the tallest populations (men around 182 cm) while populations in Southeast Asia average closer to 163 cm for men. A country-specific comparison would require different reference data.
- Adults only. Growth reference data for children and teenagers use separate age- and sex-specific percentile charts (CDC Growth Charts for ages 2-20). This calculator is not appropriate for anyone under 20.
- Biological sex, not gender. The reference populations are sex-segregated because biological sex is the primary determinant of height distribution. The calculator uses the binary male/female split that matches the NHANES data.
- No medical significance in healthy adults. Being at the 5th or 95th percentile for height is not a disease or disorder in adults. Percentile is simply a relative rank within a population.
Height percentile bands (CDC NHANES, US adults 20+)
| Percentile | Men (ft / in) | Men (cm) | Women (ft / in) | Women (cm) | Category |
|---|---|---|---|---|---|
| 3rd | 5' 5" | 165 | 5' 0" | 153 | Exceptionally short |
| 10th | 5' 7" | 170 | 5' 1" | 155 | Well below average |
| 25th | 5' 8" | 173 | 5' 2" | 157 | Below average |
| 50th | 5' 9" | 175 | 5' 4" | 162 | Average |
| 75th | 5' 11" | 180 | 5' 5" | 166 | Above average |
| 90th | 6' 1" | 184 | 5' 7" | 169 | Well above average |
| 97th | 6' 2" | 188 | 5' 8" | 173 | Exceptionally tall |
Approximate heights at key percentiles for US men and women based on CDC reference data.
Frequently asked questions
What is a good height percentile?
There is no "good" or "bad" height percentile for adults - the number is purely descriptive. The 50th percentile is exactly average, the 25th-75th range covers the middle half of the population, and most people fall somewhere in that band. Being at the 10th or 90th percentile simply means you are shorter or taller than average, which has no medical significance on its own.
How accurate is this height percentile calculator?
The calculator uses CDC NHANES 2017-2020 reference means and standard deviations, which are the best available for US adults. The normal-distribution model fits adult heights very closely, and the error-function CDF used here is accurate to better than 0.01 %. The main source of error is measurement uncertainty in how height is reported or measured.
Why does my percentile change when I select a different age group?
Average height declines slowly with age, particularly after 50, due to spinal compression and changes in posture. If you are a 70-year-old man who is 175 cm tall, you rank higher within the 70-79 reference group than you would against 20-29 year olds, because the mean for older men is lower. Using your own age group gives the most relevant comparison.
What is a z-score for height?
A z-score (also called a standard deviation score) tells you how many standard deviations your height is above or below the population mean. A z-score of 0 means exactly average; +1 means one SD above the mean (about the 84th percentile); -2 means two SDs below (about the 2nd percentile). Z-scores are used in clinical research and growth-chart analysis because they scale consistently across populations with different averages.
Can I use this calculator for children or teenagers?
No. This calculator is designed for US adults aged 20 and over. Children and teenagers are still growing, so their height must be compared against age- and sex-specific growth charts. The CDC publishes separate growth charts for ages 2-20, and there are dedicated child height percentile calculators that use those charts.
Is the average US male height really 5 ft 9 in?
Yes. The CDC NHANES 2017-2020 survey measured an average of 175.3 cm (5 ft 9.0 in) for adult men and 161.5 cm (5 ft 3.6 in) for adult women. These measurements were taken by trained staff in mobile examination centers, making them more reliable than self-reported survey data, which tends to be slightly inflated.
How do I convert a height percentile to an actual height?
Reverse the normal-CDF calculation. Find the z-score corresponding to your target percentile using the inverse normal function (e.g. the 90th percentile corresponds to z = 1.28), then calculate: height = mean + z x SD. For a US man aged 20-29 at the 90th percentile: 176.1 + 1.28 x 7.40 = 185.6 cm, or about 6 ft 1 in. The "Show your work" panel above shows all the steps for your specific inputs.