Free · Deurenberg 1991 · Private
Body Fat Percentage Calculator
Estimate your body fat % from BMI, age, and sex using a clinically validated equation. See where you sit relative to healthy ranges.
Your body fat — %
—
Frequently asked questions
How accurate is the Deurenberg body fat formula?
Standard error of estimate is ~4% compared with DEXA — accurate enough for tracking trends, not a substitute for clinical measurement.
Why does this need my age?
Body composition shifts with age. Including age in the formula improves accuracy across the adult lifespan.
Can I use this if I am very muscular?
Not reliably. The Deurenberg equation derives body fat from BMI, so anyone with high muscle mass relative to weight will get an inflated BF% reading. Use DEXA, hydrostatic weighing, or Bod Pod instead.
What is essential fat?
The minimum body fat needed for basic physiological function. For men this is 2–5%; for women, 10–13%. Going below this disrupts hormonal and immune function.