Fitness Knowledge & Calculators

The US Navy circumference method estimates body fat percentage based on height as well as neck, waist (and for women, hip) circumference. It is a recognized and practical approximation for everyday use.

Without a tape measure, we use the Deurenberg BMI method: Body fat % = 1.20 × BMI + 0.23 × age − 10.8 × gender − 5.4 (Gender: male = 1, female = 0). Both methods provide estimates; for precise values, calipers or DEXA scans are suitable.

The Body Mass Index is weight (kg) divided by height (m) squared: BMI = kg ÷ (m × m)

WHO classification: < 18.5 underweight · 18.5–24.9 normal weight · 25–29.9 overweight · ≥ 30 obesity. The BMI does not distinguish between muscle and fat mass – very muscular individuals are overestimated. For greater accuracy, combine it with the body fat calculator.

There is no single ideal weight. We show the healthy weight range based on the normal BMI (18.5–24.9) for your height as well as two classic formulas for comparison:

Broca normal weight: height (cm) − 100
Devine ideal weight: 50 (♂) or 45.5 (♀) + 0.9 × (height − 152) kg

A range is more meaningful than a rigid number – body frame and muscle mass play a major role.

We calculate protein based on body weight (lose weight 2.0 g/kg, maintain 1.8 g/kg, build muscle 2.0 g/kg) and set fat at approx. 25% of daily calories. The remaining energy comes from carbohydrates.

Caloric values: 1 g protein = 4 kcal, 1 g carbohydrates = 4 kcal, 1 g fat = 9 kcal.