About Compare My Height

Compare My Height is run by a single independent builder as five free height tools built around one idea: show the math, not just the number. Every tool states the formula it runs, works a real example through with the tool's own defaults, and shows exactly where a cited figure comes from -- exact unit-conversion constants, and the specific published table behind every percentile or average-height figure.

How the tools work

Every tool on this site -- the height comparison, the comparison chart, the percentile calculator, the unit converter, and the difference calculator -- routes unit conversions and percentile interpolation through one shared set of functions, rather than each tool re-implementing its own math. Every formula is checked against a hand-derived expected value in the site's own test suite before it ships.

Where the figures come from

The unit-conversion constant (1 inch = 2.54 cm) is an exact international definition, not a rounded approximation. The adult height percentile data comes directly from CDC/NCHS, Anthropometric Reference Data for Children and Adults: United States, 2015–2018 (Vital and Health Statistics, Series 3, No. 46, January 2021) -- Table 11 (height in centimeters, males aged 20 and over, all races and Hispanic-origin groups, ‘20 and over’ row), p. 15 and Table 9 (height in centimeters, females aged 20 and over, all races and Hispanic-origin groups, ‘20 and over’ row), p. 13 -- transcribed from the published PDF, not estimated. The reference-object heights (an interior door, a basketball hoop) are widely documented standards, cited individually where they're used; anything shown only as "typical" (like a refrigerator height) is labeled that way rather than presented as a fixed spec.

What it doesn't do

Every height tool here covers adults (20 and over) only -- this site deliberately doesn't offer a child-growth or height-prediction tool. Percentile figures describe where a height falls in the adult population; they are not a medical, health, or growth assessment, and Compare My Height isn't affiliated with the CDC, the NBA, FIBA, or any door or appliance manufacturer whose products are referenced as scale objects. See Terms.

Every tool

• Height Comparison -- Compare up to six people or objects side by side as true-to-scale silhouettes, with average-adult and common-object presets, a scale ruler, and a shareable link.
• Height Comparison Chart -- A reference table from 4'0" to 7'0" in 1-inch steps, with the equivalent in inches, centimeters, meters, and the adult percentile for men and women at each height.
• Height Percentile Calculator -- Find where an adult height falls among US adults aged 20 and over, interpolated from CDC/NHANES percentile data for men and women.
• Height Converter -- Convert a height between feet and inches, centimeters, meters, and decimal inches instantly, with a quick-reference table of common heights.
• Height Difference Calculator -- Calculate the exact difference between two heights in inches, centimeters and percent, plus how many of the shorter height stack up to the taller one.

Corrections

If a figure or citation here is wrong or out of date, email hello@comparemyheight.com.