Body fat percentage is the proportion of fat to total body weight. Healthy ranges: Men 10-20%, Women 18-28%. Essential fat (minimum needed): Men 2-5%, Women 10-13%. Athletes often have 6-13% (men) or 14-20% (women). This is a better health indicator than BMI alone because it accounts for muscle mass.
📂 Health
💪 Body Fat Calculator
Calculate your body fat percentage using measurements. Works without expensive equipment — just a tape measure. Understand your body composition and set realistic fitness goals.
✏️ Enter Your Values
📍 Body Measurements (use a tape measure at widest points)
✨ Your Result
🦉Owl's Explanation
💪
Fill in the values above and click Calculate ✨
✅ Trusted Tool
The 365tool.net Body Fat Calculator uses the US Navy circumference formula validated for general population fitness assessment. Free, no equipment needed beyond a tape measure. For clinical body composition analysis, consult a health professional.
🤔 How Does This Work?
Our Body Fat Calculator uses the US Navy method:
Male: % = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76
Female: % = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387
This formula was developed by the US Department of Defense and is widely used for fitness assessments. It requires only a tape measure and is surprisingly accurate for most people.
❓ Frequently Asked Questions
What is a healthy body fat percentage?▼
For men: Essential fat 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+. For women: Essential fat 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+. These are general guidelines — individual health varies.
Is body fat percentage better than BMI?▼
Yes, for most people. BMI only uses weight and height. A very muscular person might have 'overweight' BMI but very low body fat. Body fat % directly measures fat vs muscle composition. However, BMI is easier to measure without a tape measure.
How do I measure waist and hip correctly?▼
Waist: measure at the narrowest point, usually just above the belly button, while relaxed (do not suck in). Hip: measure at the widest point of the hips and buttocks. Neck: measure just below the Adam's apple. All measurements should be taken in the morning without clothes for consistency.
Can I reduce body fat in specific areas?▼
No — spot reduction is a myth. You cannot choose where your body loses fat. Fat loss happens throughout the body when you are in a caloric deficit. However, targeted exercises do build muscle in specific areas, improving their appearance even before fat loss.
How accurate is the Navy formula?▼
The US Navy formula has about 3-4% margin of error, which is acceptable for general health tracking. For clinical precision, DEXA scan is most accurate (1-2% error). Skinfold calipers with trained technician are also accurate. The Navy method is good for home tracking.
For men: Essential fat 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+. For women: Essential fat 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+. These are general guidelines — individual health varies.
Is body fat percentage better than BMI?▼
Yes, for most people. BMI only uses weight and height. A very muscular person might have 'overweight' BMI but very low body fat. Body fat % directly measures fat vs muscle composition. However, BMI is easier to measure without a tape measure.
How do I measure waist and hip correctly?▼
Waist: measure at the narrowest point, usually just above the belly button, while relaxed (do not suck in). Hip: measure at the widest point of the hips and buttocks. Neck: measure just below the Adam's apple. All measurements should be taken in the morning without clothes for consistency.
Can I reduce body fat in specific areas?▼
No — spot reduction is a myth. You cannot choose where your body loses fat. Fat loss happens throughout the body when you are in a caloric deficit. However, targeted exercises do build muscle in specific areas, improving their appearance even before fat loss.
How accurate is the Navy formula?▼
The US Navy formula has about 3-4% margin of error, which is acceptable for general health tracking. For clinical precision, DEXA scan is most accurate (1-2% error). Skinfold calipers with trained technician are also accurate. The Navy method is good for home tracking.