Body Fat Calculator

Punch in your height, weight, neck, and waist measurements — plus hips if you're measuring a female body — and this calculator returns your body fat percentage in seconds using the U.S. Navy method, one of the most widely used tape-measure formulas outside a lab. You also get a breakdown of your actual fat mass versus lean mass in pounds or kilograms, along with the body composition category you fall into: essential fat, athletic, fitness, acceptable, or obese.

It's a practical snapshot, not a medical assessment, but it gives you a concrete number to track over time — far more informative than weight alone. If you're already monitoring your numbers here, pairing this with the TDEE Calculator lets you line up body composition data alongside your calorie maintenance targets. Both tools live in Health & Fitness and work well together for anyone building a clearer picture of their baseline.

All you need is a flexible tape measure and about two minutes — works best when you take measurements first thing in the morning before eating.