体脂肪率計算機
米海軍方式で体脂肪率を計算します。
Body Fat Percentage Calculator
Calculate your body fat percentage using the US Navy Method - a scientifically validated measurement technique
📏 How to Measure
Height: Stand straight, measure from floor to top of head
Neck: Measure just below the larynx (Adam's apple), perpendicular to body axis
Waist (Men): Measure at the level of your navel, horizontally
Waist (Women): Measure at the narrowest point, usually just above the navel
Your Body Fat Percentage
18.6%
Athletes
Athletic/fit
Body Composition
Your Measurements
Height170.0 cm
Neck37.0 cm
Waist85.0 cm
Body Fat Percentage Standards
Men
| Category | Age ≤ 39 | Age ≥ 40 |
|---|---|---|
| Essential Fat | < 8% | < 8% |
| Athletes | 8-19% | 8-21% |
| Fitness | 20-24% | 22-26% |
| Average | 25-29% | 27-31% |
| Obese | ≥ 30% | ≥ 32% |
Women
| Category | Age ≤ 39 | Age ≥ 40 |
|---|---|---|
| Essential Fat | < 21% | < 21% |
| Athletes | 21-32% | 21-33% |
| Fitness | 33-38% | 34-39% |
| Average | 39-39% | 40-41% |
| Obese | ≥ 40% | ≥ 42% |
📐 About the US Navy Method
The US Navy Body Composition method is a scientifically validated technique developed by the Department of Defense. It uses circumference measurements to estimate body fat percentage.
Formula (Men):
Body Fat % = 495 / (1.0324 - 0.19077 × log₁₀(waist - neck) + 0.15456 × log₁₀(height)) - 450
Formula (Women):
Body Fat % = 495 / (1.29579 - 0.35004 × log₁₀(waist + hip - neck) + 0.22100 × log₁₀(height)) - 450
Accuracy: The Navy Method has a margin of error of ±3-4% when compared to more advanced methods like DEXA scans or hydrostatic weighing.
⚠️ Important Notes
- •Take measurements at the same time of day for consistency (morning is best)
- •Measure on bare skin, not over clothing
- •Keep the tape measure snug but not tight - don't compress the skin
- •Take multiple measurements and use the average for better accuracy
- •This method may be less accurate for very lean or obese individuals
- •Track trends over time rather than focusing on a single measurement