Four body composition calculators in one: Navy body fat percentage, lean body mass, ideal body weight and ponderal index. Switch methods and get instant results.
Body fat percentage—%
Related tools
This page replaces the individual converters below, which remain available as standalone pages.
Navy body fat uses the U.S. Navy circumference formula (waist, neck, and hip for women) — the most practical tape-measure method. Lean body mass uses the Boer equation. Ideal weight uses the Devine formula, the clinical standard. Ponderal index (weight over height cubed) is the corpulence index some researchers prefer over BMI.
How accurate are they
Tape methods land within 3-4% of DEXA scans when measurements are careful — measure waist at the navel, relaxed, and keep the tape level. These are estimates for healthy adults, not medical diagnoses.
Navy body fat, when measured carefully, correlates well with DEXA. Lean mass and ideal weight are equations with wider error bands — useful as targets, not precise readings.
How do I measure my waist correctly?
At the navel (belly button), tape horizontal and snug but not compressing, after exhaling normally. Measure neck just below the Adam's apple, hip at the widest point.
What is a healthy body fat percentage?
Roughly 10-20% for men and 18-28% for women by most fitness standards; athletes run lower. Essential fat is about 3-5% for men and 10-13% for women.
Ponderal index vs BMI?
Ponderal index divides by height cubed instead of squared, which some researchers argue scales better across heights. Typical adult values fall between 11 and 15 kg/m³.
Is this medical advice?
No. These are general estimates. Consult a professional for health decisions, especially if you have a medical condition.