Health references

Body fat estimate from BMI

Enter your values to see the result, check the formula and copy your calculation.

Your inputs1

Min. 30 · Max. 400

Min. 100 · Max. 250

Min. 18 · Max. 100

Decimal point or comma accepted. No registration.

Your result2

Enter your values, then calculate.

Your calculation stays in your browser.

The formula, explained

body fat % ≈ 1.2×BMI + 0.23×age − 10.8×coefficient − 5.4

Deurenberg’s adult statistical estimate is not a body measurement or diagnosis. Coefficient: 1 male, 0 female. Individual error can be substantial, particularly in athletes. Do not use during pregnancy or for children.

Source and reference : Deurenberg et al., 1991 ↗

An example to check

Using the starting values below, the calculation gives:

Weight (kg): 65Height (cm): 170Adult age: 30Equation coefficient: Female
28.4896193772 %

How to use this tool

Check the required inputs: weight (kg), height (cm), adult age.

Choose the units and options that match your task. Calculate, check the result and use Copy or Print to keep a record. Rounding applies to the display; keep more precision in intermediate steps.

Can I use a decimal comma?

Yes. Numeric fields accept 12.5 or 12,5 and spaces for thousands, such as 1 234.50. Do not mix a point and comma in one number.

Where are my inputs processed?

Calculations run in your browser. Form values are not sent to Analytics. Copying, printing, sharing or opening an external service is your choice.

Method and interface checked on 2026-09-12 · Report an error