Height Calculator
Adjust the inputs below. Results update as you type.
How it works
Mid-parental height: boys = (father's height + mother's height + 5 inches) / 2; girls subtract 5 inches instead. Target range is ±2 inches of mid-parental height. Growth plates fuse at 16–18 in girls and 18–21 in boys. Bone age X-ray provides a more accurate prediction. Nutrition, sleep, and chronic illness can shift actual height above or below genetic potential.
Input guidance
- Confirm date/time/unit settings before comparing outputs.
- If a task has optional fields, run both with and without them to understand impact.
- Save scenario variants when making practical decisions.
The formula
Convert height between units (1 inch = 2.54 cm; 1 foot = 12 inches). Child height predictions often use parental average plus or minus an adjustment by sex.
Worked example
5 feet 10 inches = 70 inches × 2.54 = 177.8 cm. A common adult-height prediction averages the parents' heights with a 2.5-inch sex adjustment.
More examples to test
- Quick-pass example: run default assumptions for a first estimate.
- Refined example: update one assumption at a time to isolate impact.
How to interpret results
Use outputs as operational estimates and pair them with local constraints, business rules, or provider requirements.
When this can be inaccurate
Utilities can miss local policy details, special-case rules, and environment-specific constraints.
Change history
- July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.
Site-wide corrections also appear on the corrections log.
Find productivity tools for everyday workflows
General recommendation, not professional advice.
Frequently asked questions
How do I convert feet and inches to cm?+
Turn the height fully into inches, then multiply by 2.54. 5'6" is 66 inches × 2.54 = 167.6 cm.
How accurate are child height predictions?+
The mid-parental method gives a rough estimate within a few inches; genetics, nutrition, and health all affect the final result.
When do people stop growing?+
Most reach adult height by the late teens once growth plates close, though timing varies by individual and sex.
Why are outputs slightly different from another tool?+
Different tools can use different rounding rules, default assumptions, and treatment of edge cases.
How can I improve estimate reliability?+
Use verified inputs from real records and re-run calculations after major assumption changes.