Body Fat Calculator (Navy Method)

About the Body Fat Calculator (Navy Method)

Body Fat Calculator (Navy Method) gives a surprisingly accurate body-fat estimate using just a tape measure and your height. Originally developed for the U.S. Navy, it's within ±3% of DEXA-scan accuracy for most people.

How to use

1. Select gender and enter height in centimetres.
2. Measure neck (below larynx), waist (at navel) and — for women — hip (widest point).
3. Click Calculate for body-fat % and category.

Benefits & key features

• Free, fast and surprisingly accurate (±3% vs DEXA).
• No equipment beyond a soft tape measure.
• Repeatable weekly to track progress.
• Pairs with BMI and TDEE for a complete body-composition picture.

Pro tip

Measure first thing in the morning, after the bathroom and before any food or water, for the most consistent week-to-week comparison.

Why choose toolsfy for Health & Fitness tools?

A BMI calculator that harvests your email address, a TDEE estimator that upsells coaching — the health-and-fitness web is riddled with dark patterns. toolsfy's tools compute the same peer-reviewed equations (Mifflin-St Jeor for TDEE, WHO BMI bands, U.S. Navy body-fat formula) without asking for anything more than the numbers needed to run the math.

Common use cases

• Personal trainers running quick BMI and body-fat estimates for new clients during their first consultation, with nothing logged or stored.
• Home cooks planning a short calorie-deficit cycle and wanting the daily target in plain numbers rather than a vague "app score".
• Patients preparing for a doctor's appointment by converting a mg/dL blood-sugar reading into mmol/L (or vice versa) before their consult.

Frequently asked questions