Body Fat Percentage Calculator
Estimate your body fat percentage with the proven U.S. Navy tape-measure method — instant BFP, fat mass and lean mass results.
Tool Interface
How to use
- Choose your units (Metric or Imperial) and gender.
- Measure with a tape: neck just below the Adam's apple, waist at the navel (men) or narrowest point (women), hips at the widest point (women).
- Enter your age, height, weight and measurements, then press Calculate.
- Your estimated body fat %, category, fat mass and lean mass appear instantly — all computed in your browser.
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About This Tool
Introduction
A body fat percentage calculator tells you far more than the bathroom scale ever could — and Trencada's free Body Fat Percentage Calculator uses the proven U.S. Navy tape-measure method to estimate your body fat in seconds. Enter your age, height, weight, and a few tape measurements (neck, waist, and hips for women) and get your estimated body fat percentage, category, fat mass, and lean body mass instantly. Everything runs entirely in your browser — no signup, no downloads, and nothing you enter is ever uploaded or stored.
How to Use
- Choose your units — Metric (cm / kg) or Imperial (in / lb) — and select Male or Female.
- Measure with a flexible tape: neck just below the Adam's apple, waist at the navel (men) or the narrowest point (women), and hips at the widest point (women only).
- Enter your age, height, weight, and measurements, then press Calculate.
- Your estimated body fat %, category (Essential / Athletes / Fitness / Average / Obese), fat mass, and lean body mass appear instantly.
- Use Reset to clear everything and start over.
Key Features
- U.S. Navy body fat formula — the standard tape-measure method used by the military
- Metric and Imperial support with automatic unit conversion
- Gender-specific formulas and healthy-range categories
- Instant results: body fat %, category label, fat mass, and lean body mass
- Color-coded category badge so you can see where you stand at a glance
- Inline validation with clear messages (no popups)
- Fully responsive — works on phones, tablets, and desktops
Why Choose Trencada
Every Trencada tool is free forever with no hidden costs, no accounts, and no installation. The Body Fat Percentage Calculator runs 100% in your browser, so your measurements stay completely private — they never leave your device.
Frequently Asked Questions (FAQ)
- How accurate is the U.S. Navy body fat method? It is a well-established estimate based on large military studies, typically within 3–4% of more expensive methods like DEXA scans. It is an estimate, not a medical measurement.
- What measurements do I need? Men: height, neck, and waist. Women: height, neck, waist, and hips. Plus your age and weight for the fat/lean mass breakdown.
- Is this medical advice? No. This tool provides estimates for informational and fitness-tracking purposes only. Consult a healthcare professional for medical guidance.
- Do I need to create an account? No. Like all Trencada tools, it works instantly with no signup or login.
- Is my data private? Yes. The calculation happens entirely in your browser — your measurements are never uploaded, stored, or tracked.