Body Fat Calculator
The Body Fat Calculator helps estimate your total body fat percentage using specific body measurements. You can choose between Metric Units (International System of Units, SI) or US Units for convenience. For the most accurate results, measure to the nearest 0.5 cm (1/4 inch). This calculator uses the U.S. Navy Method and the BMI Method to provide comprehensive body fat estimates.
Input Fields:
- Gender:
Select male or female - Age:
Example: 25 years - Weight:
Example: 70 kg - Height:
Example: 178 cm - Neck Circumference:
Example: 50 cm - Waist Circumference:
Example: 96 cm - Hip Circumference (Women Only):
Measure at the widest point
Results:
Body Fat Percentage: 15.7%
Save this calculation for future reference.
| Metric | Value |
|---|---|
| Body Fat (U.S. Navy Method) | 15.7% |
| Body Fat Category | Fitness |
| Body Fat Mass | 11.0 kg |
| Lean Body Mass | 59.0 kg |
| Ideal Body Fat for Given Age | 10.5% |
| Body Fat to Lose to Reach Ideal | 3.6 kg |
| Body Fat (BMI Method) | 16.1% |
Body Fat Categories
American Council on Exercise (ACE) Classification:
| Category | Women | Men |
|---|---|---|
| Essential Fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32%+ | 25%+ |
Jackson & Pollock Ideal Body Fat Percentages:
| Age | Women | Men |
|---|---|---|
| 20 | 17.7% | 8.5% |
| 25 | 18.4% | 10.5% |
| 30 | 19.3% | 12.7% |
| 35 | 21.5% | 13.7% |
| 40 | 22.2% | 15.3% |
| 45 | 22.9% | 16.4% |
| 50 | 25.2% | 18.9% |
| 55 | 26.3% | 20.9% |
Understanding Body Fat
Body fat, scientifically known as adipose tissue, plays several vital roles in the body. It stores energy, secretes hormones, and provides insulation and cushioning. There are two main types of body fat:
- Essential Fat:
- Necessary for basic bodily functions and reproductive health.
- Men: 2–5%
- Women: 10–13%
- Storage Fat:
- Accumulates in adipose tissue, either as subcutaneous fat (under the skin) or visceral fat (around internal organs).
- Excess storage fat can lead to health complications.
Health Implications of Body Fat
Risks of Excess Body Fat:
- Obesity: A leading preventable cause of death worldwide, linked to cardiovascular disease, stroke, diabetes, and certain cancers.
- Hormonal Imbalance: Excess fat, especially visceral fat, disrupts hormone regulation and increases inflammation.
- Insulin Resistance: Can lead to type 2 diabetes.
- Cholesterol Levels: High visceral fat is associated with increased LDL ("bad cholesterol") and decreased HDL ("good cholesterol").
Risks of Insufficient Body Fat:
- Hormonal deficiencies.
- Impaired reproductive and immune functions.
- Loss of essential cushioning and insulation.
Measuring Body Fat Percentage
U.S. Navy Method:
This method uses body circumference measurements to estimate body fat percentage. The formulas differ for men and women:
For Men:
- US Units:
BFP = 86.010 × log10(abdomen - neck) - 70.041 × log10(height) + 36.76 - Metric Units:
BFP = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450
For Women:
- US Units:
BFP = 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387 - Metric Units:
BFP = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450
BMI Method:
This method estimates body fat percentage using Body Mass Index (BMI), age, and gender.
For Adult Males:
BFP = 1.20 × BMI + 0.23 × Age - 16.2
For Adult Females:
BFP = 1.20 × BMI + 0.23 × Age - 5.4
For Boys:
BFP = 1.51 × BMI - 0.70 × Age - 2.2
For Girls:
BFP = 1.51 × BMI - 0.70 × Age + 1.4
Fat Mass and Lean Mass Calculations
- Fat Mass (FM):
FM = Body Fat Percentage × Weight - Lean Body Mass (LM):
LM = Weight - Fat Mass
Limitations and Accuracy
While the U.S. Navy and BMI methods provide useful estimates, they are not 100% accurate. For more precise measurements, consider methods like bioelectric impedance analysis or hydrostatic density testing.
Related Tools:
- BMI Calculator
- Calorie Calculator
- Ideal Weight Calculator
References:
- American Council on Exercise (ACE) Body Fat Categorization.
- Jackson & Pollock Ideal Body Fat Percentages.
- World Health Organization (WHO) on Obesity and Health Risks.