Body Fat Calculator
Estimate adult body fat percentage from BMI, age and sex using a commonly cited BMI-based screening equation.
Calculator workspace
Enter your values and use the original calculator functions in the updated premium workspace.
Enter your information to calculate your body fat percentage:
Your body fat percentage is:
How This Body Fat Calculator Works
Estimate adult body fat percentage from BMI, age and sex using a commonly cited BMI-based screening equation. The rebuilt page uses calculator-specific logic rather than the legacy page script. Inputs are validated before calculation, and supporting figures are shown with the headline result so the arithmetic is easier to check.
Core method: Body fat % ≈ 1.20 × BMI + 0.23 × age − 10.8 × sex − 5.4, where sex = 1 for male and 0 for female.
How to Use It
- Enter the values requested in the calculator workspace.
- Select Calculate and correct any input highlighted by validation.
- Review the main answer, supporting figures and formula/method shown with the result.
- Use Copy Result, Share Result or Save Result Image if you need to keep the calculation.
Worked Example
The calculator first derives BMI from weight and height, then applies the age- and sex-adjusted estimate.
Common Uses
- Fitness screening
- Body-composition estimates
- Progress tracking
Common Search Questions About Body Fat Calculator
How do I calculate this?
Estimate adult body fat percentage from BMI, age and sex using a commonly cited BMI-based screening equation.
What formula does this calculator use?
Body fat % ≈ 1.20 × BMI + 0.23 × age − 10.8 × sex − 5.4, where sex = 1 for male and 0 for female.
How can I get the result quickly?
Enter the required values and select Calculate. The rebuilt mobile interface brings the result into view instead of leaving it far below the form.
Important Limitations
This BMI-based equation is a rough population estimate and can be inaccurate for athletes, older adults and many body types. It is not a diagnostic measurement.
Frequently Asked Questions
Does the calculator upload my inputs?
No. The calculation runs in the browser and does not require an account.
Can I calculate again with different values?
Yes. Change any input and calculate again to compare scenarios.
Should I verify important results?
Yes. For high-impact financial, legal, health, engineering or contractual decisions, compare calculator output with current source information and appropriate professional guidance.