Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method. No calipers needed — just a tape measure.
How to Use the Body Fat Calculator
Select your gender and enter your height, neck, and waist measurements in centimetres. Women also need to enter their hip circumference. Use a soft tape measure and measure each site twice for accuracy.
The Extended Calculator below adds a Jackson-Pollock 3-site skinfold tab and a visual body fat zones gauge. The Professional Calculator adds FFMI (Fat-Free Mass Index), lean mass targets, and body recomposition planning.
Body Fat Classification Table
| Category | Male Range | Female Range |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athletic | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Obese | 25–50% | 32–50% |
US Navy Formula
Male: 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450
Female: 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450
All measurements in centimetres.
Body Fat Categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athlete | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Body Recomposition Targets
| Target Body Weight | 75.2 kg |
| Fat to Lose | 4.8 kg |
| Estimated Time to Goal | 16 weeks |
| Recommended Daily Calories | 2490 kcal (mild deficit) |
FFMI Reference (Fat-Free Mass Index)
FFMI Formula: Lean Mass (kg) ÷ Height (m)²
FFMI measures muscularity independent of fat. Natural male athletes rarely exceed 25; values above this are associated with anabolic steroid use in research literature.
| Male FFMI | Category | Female FFMI |
|---|---|---|
| <18 | Below Average | <15 |
| 18–20 | Average | 15–17 |
| 20–22 | Above Average | 17–19 |
| 22–25 | Excellent | 19–21 |
| >25 | Elite / Suspicious | >21 |