📏 Body Fat Calculator

Body fat percentage — why it matters more than weight

Your total body weight is a blunt instrument. Two people can weigh exactly the same but have very different body compositions — one might have 15% body fat and significant muscle mass, the other 35% body fat and minimal muscle. The health implications are completely different.

Body fat percentage gives you a better picture of body composition, but measuring it accurately is harder than stepping on scales. Various methods exist with different trade-offs:

• Tape measure methods (Navy formula, waist-to-height): Convenient and reasonably accurate for most people. This calculator uses the US Navy method.
• Bioelectrical impedance (smart scales): Consumer scales send a small electrical current through the body. Quick and convenient but accuracy varies with hydration levels — results can swing 3–5% depending on when you measure.
• Skinfold calipers: Trained practitioners pinch and measure subcutaneous fat at specific sites. Accurate when done correctly, but operator-dependent.
• DEXA scanning: The gold standard — accurate, consistent, and provides a detailed breakdown by body segment. Available at some clinics and universities for $50–100.