Body Fat Percentage from BMI Calculator
A quick body-fat estimate when you only know height and weight.
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Your results
Body Fat Percentage from BMI Calculator by TheCalcTools
How the Body Fat Percentage from BMI Calculator works
Enter your sex, age, height and weight.
BMI is weight divided by height squared.
The Deurenberg equation turns BMI, age and sex into a body fat estimate.
The formula
Worked example
Using the default values shown in the calculator:
| Sex | Male |
|---|---|
| Age (years) | 35 |
| Height (cm) | 178 |
| Weight (kg) | 82 |
- BMI = 82 ÷ 1.78² = 25.9.
- Body fat ≈ 22.9%, so about 18.8 kg fat and 63.2 kg lean mass.
Result:
| BMI | 25.9 |
|---|---|
| Estimated body fat | 22.9% |
| Fat mass (kg) | 18.8 |
| Lean mass (kg) | 63.2 |
Frequently asked questions
How accurate is it?
It is a rough population estimate. Muscular people are overestimated and people with low muscle mass underestimated. DEXA scans or skinfold measurements are more reliable.
What is a healthy body fat range?
Roughly 10–20% for men and 18–28% for women of average age, though ranges differ by source and age.
Sources and further reading
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This calculator gives general estimates for information and education. It is not medical advice and does not diagnose anything. Talk to a qualified health professional about your own situation. See our disclaimer.