Body Fat Percentage & Healthy Weight Range Calculator

Estimate your body fat percentage using the U.S. Navy circumference method and determine your healthy weight range based on BMI guidelines (18.5–24.9).

Formulas Used

U.S. Navy Body Fat Percentage (circumference method):

Male:
%BF = 86.010 × log₁₀(waist − neck) − 70.041 × log₁₀(height) + 36.76

Female:
%BF = 163.205 × log₁₀(waist + hip − neck) − 97.684 × log₁₀(height) − 78.387

All measurements in centimetres.

BMI: BMI = weight (kg) ÷ height² (m²)

Healthy weight range: weight = BMI × height² (m²), for BMI 18.5–24.9

Fat mass: Fat Mass = body weight × (BF% ÷ 100)
Lean mass: Lean Mass = body weight − Fat Mass

Assumptions & References

  • Body fat is estimated using the U.S. Navy circumference method (Hodgdon & Beckett, 1984), validated against hydrostatic weighing.
  • Healthy weight range is based on a BMI of 18.5–24.9 (WHO / NIH guidelines).
  • Body fat categories follow American Council on Exercise (ACE) guidelines.

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