Health & fitness
Adult BMI
Calculate body mass index from weight and height.
Calculators / Health & fitness / Body fat estimate
Body fat estimate calculator
Estimate body-fat percentage from BMI, age and sex coefficient.
On this page
Estimated body fat20.65%
Calculator controls
How to calculate
Estimate body-fat percentage from BMI, age and sex coefficient.
Estimated body fat = 1.2*bmi+0.23*age-10.8*sex-5.4
Worked example
BMI: 24; Age: 35; Sex coefficient (1 male, 0 female): 1.
Estimated body fat: 20.65 %.
Assumptions and limits
Population equations can be inaccurate for individuals, athletes, older adults and some ethnic groups. Do not use this for diagnosis.
Results are rounded for display; calculations use unrounded values. Read our calculation methodology.
Understanding the result
Estimate body-fat percentage from BMI, age and sex coefficient. The displayed figures use the inputs and formula shown on this page.
When this tool is useful
Use the body fat estimate to compare a scenario, check an estimate, or verify a manual calculation.
Understanding your inputs
| Input | What to enter |
|---|---|
| BMI | Enter a number of at least 0.000001 and no more than 1000000000000. |
| Age | Enter a number of at least 18 and no more than 120. |
| Sex coefficient (1 male, 0 female) | Enter a number of at least 0 and no more than 1. |
Frequently asked questions
What should I check before using the body fat estimate result?
Population equations can be inaccurate for individuals, athletes, older adults and some ethnic groups. Do not use this for diagnosis.
Is this body fat estimate result exact?
It is exact for the stated mathematical model and entered values. Real-world results can differ when rates, timing, fees, definitions or measurement conditions differ.