Body Fat Calculator

Estimate your body fat percentage using the U.S. Navy body fat formula as the primary result, plus a BMI-based estimate for comparison. Supports both Imperial (in/lb) and Metric (cm/kg) units.

Body Fat % (U.S. Navy)
0%
Estimated Body Fat % (BMI)
0%

About the Body Fat Calculator

The Body Fat Calculator helps you estimate what percentage of your body weight comes from fat. It uses two methods: the U.S. Navy body fat formula as the primary result and a BMI-based body fat estimate as a secondary reference.

Formulas Used

1. U.S. Navy Body Fat Formula (primary)


Men:
Body Fat % = 495 / (1.0324 − 0.19077 × log₁₀(waist − neck)
                    + 0.15456 × log₁₀(height)) − 450

Women:
Body Fat % = 495 / (1.29579 − 0.35004 × log₁₀(waist + hip − neck)
                    + 0.22100 × log₁₀(height)) − 450

2. BMI-based Estimate (secondary)


Body Fat % = 1.20 × BMI − 10.8 × Gender − 5.4

where:
  BMI    = weight(kg) / [height(m)]²
  Gender = 1 for males, 0 for females

Healthy Body Fat Ranges

  • Men: 10–20% (fit), 20–25% (average)
  • Women: 18–28% (fit), 25–32% (average)

Using This Calculator

  • Select your gender and unit system.
  • Enter your height, neck, waist, and (for women) hip measurements.
  • Enter your weight to enable the BMI-based estimate.
  • Compare the Navy result with the BMI-based result for context.

This calculator is a useful screening tool for fitness and health – but it is not a medical diagnosis. For precise body composition analysis, methods like DEXA scans, calipers, or professional assessment may be needed.