Body Fat Calculator
U.S. Navy method body-fat percentage from neck, waist, and (for women) hip circumferences. Accurate to within ±3-4% in the general population.
How to use
- 1
Measure your neck just below the larynx with the tape level. Take 3 measurements, use the average.
- 2
Measure your waist. Men: at the navel. Women: at the smallest point above the navel. Don't pull tight.
- 3
Women: also measure hip at the widest point around the buttocks.
- 4
Enter your height. The calculator returns body fat percentage instantly and shows where you fall on the ACE category scale (essential, athlete, fitness, average, obese).
- 5
Measure at the same time of day (morning, after waking) under the same conditions for consistent tracking. Body composition changes slowly — 1-2% per month is fast progress.
Frequently asked questions
Compared to DEXA (the gold-standard body composition scan), the Navy method is accurate to within ±3-4% for the general adult population. It's less accurate for very lean (under 8%) and very heavy (over 35%) bodies, and for those with unusual body shapes. For weight-loss tracking, the method is consistent — if your number drops, you're losing fat — even if the absolute figure is slightly off.
For men: 14-17% is considered fit, 18-24% is average healthy, 6-13% is athletic. For women: 21-24% is fit, 25-31% is average healthy, 14-20% is athletic. Going below the 'essential' threshold (5% for men, 13% for women) disrupts hormones — for women specifically, periods stop and bone density drops. Going above the 'obese' threshold (25% men, 32% women) significantly increases cardiovascular and metabolic risk.
Body fat percentage matters more. BMI doesn't distinguish muscle from fat — a 90 kg bodybuilder at 8% body fat will register as 'obese' on BMI while being objectively healthier than a 75 kg sedentary person at 30% body fat. BMI is a quick screen useful for population-level health stats. Body fat % is the better individual metric for fitness, health, and tracking progress.
Use a soft flexible tape (cloth, not metal). Measure first thing in the morning, before eating or drinking. Stand relaxed, breathe out normally. Keep the tape parallel to the floor at every site. Take 3 measurements at each site (neck, waist, hip) and use the average. Track on the same day of the week each week — body composition fluctuates by 1-2 cm in waist day-to-day from food/water/digestion.
Generally no. Consumer-grade bioelectrical impedance scales (BIA) vary widely by hydration, recent food intake, and even what time of day you weigh. They can be off by 5-10% on any given reading. The Navy method, while a circumference estimate, is more repeatable. The most accurate at-home methods are 3-site or 7-site skinfold calipers (if you can find a trained person) and certain newer BIA devices like InBody clinic scanners. DEXA at AED 350-500 in Dubai is the medical gold standard.
Because the typical body fat distribution differs. Women carry more essential fat — about 10-13% is the physiological minimum for healthy hormone function, vs 2-5% for men. Women also distribute fat differently (hips, thighs, breasts) which is why the women's formula includes hip circumference. The thresholds for 'lean' and 'athletic' are higher for women across the board, not because women are unhealthier, but because their healthy baseline is biologically higher.
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Source: Hodgdon & Beckett (1984) U.S. Navy circumference equations, American Council on Exercise body-fat norms · Last verified 2026-06. Original Navy study. This tool provides estimates only and is not legal, tax or financial advice. Always verify your specific situation with the relevant UAE authority or a licensed advisor before taking action.