How accurate is US Navy method?
Approximately 3-4% error, better than BMI-based but not as precise as DEXA.
Health Fitness
Estimator of Body Fat Percentage
Use the US Navy method to assess your estimated body fat.
Track Your Fitness Progress
Monitor changes in body composition to stay motivated.
What this calculator does
The US Navy method estimates body fat using circumference measurements. Developed in 1984, it has ~3-4% error and is widely adopted by military and fitness facilities.
How it works
Men: measure neck and waist. Women: measure waist, hip, and neck. Apply to logarithmic equations.
Formula
Men: 86.010 × log₁₀(waist-neck) - 70.041 × log₁₀(height) + 36.76. Women: 163.205 × log₁₀(waist+hip-neck) - 97.684 × log₁₀(height) - 78.387.
Tips for using this calculator
- Measure consistently: neck below Adam's apple, waist at navel for men
- Take measurements in morning when well-hydrated
- Record all measurements alongside calculated percentage
- Remember 3-4% error margin—focus on trends
- Combine with waist circumference for cardiovascular risk
Frequently asked questions
Why different measurements for men and women?
Men accumulate fat primarily in abdomen; women distribute across waist, hips, and throughout body.
What body fat ranges should I aim for?
Healthy: men 18-25%, women 25-32%. Athletes may sustain lower temporarily.