Calculadora de Gordura Corporal Online Grátis
Body fat % using US Navy method with category classification
This body fat calculator uses the US Navy circumference method, which estimates body fat percentage from measurements of the neck, waist, and hips — no calipers or expensive equipment required. The method is validated to within 3–4% of DEXA scan results for most people, making it one of the most practical field-based assessments available.
Frequently Asked Questions
Sobre Esta Calculadora
Body fat percentage is a more direct measure of body composition than BMI because it distinguishes between fat mass and lean mass (muscle, bone, organs, water). Two people with identical BMI scores can have vastly different health profiles if one is muscular and the other has high fat mass.
The US Navy method was developed for military fitness assessments and is a practical alternative to expensive methods like DEXA scanning or hydrostatic weighing. It uses circumference measurements — which correlate with subcutaneous fat distribution — to estimate total body fat using a logarithmic formula.
Accuracy is best when measurements are taken consistently: use a flexible tape measure, measure at the same time of day, and take three readings per site and average them. For women, the formula also incorporates hip circumference since women carry proportionally more fat in the hip region.
Esta calculadora usa o método da circunferência da Marinha dos EUA, que estima a porcentagem de gordura corporal a partir das medidas do pescoço, cintura e quadril.
Fórmula
Men: BF% = 495/(1.0324 - 0.19077×log₁₀(waist-neck) + 0.15456×log₁₀(height)) - 450
Exemplo Resolvido
Body fat estimation for a 30-year-old man
Entradas:
- Sex: Male
- Height: 180 cm
- Waist circumference: 88 cm
- Neck circumference: 38 cm
Passo a Passo:
- Apply US Navy formula for men:
- BF% = 495 / (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450
- Waist − neck = 88 − 38 = 50 cm; log₁₀(50) = 1.6990
- log₁₀(180) = 2.2553
- Denominator = 1.0324 − (0.19077 × 1.6990) + (0.15456 × 2.2553)
- = 1.0324 − 0.3241 + 0.3486 = 1.0569
- BF% = 495 / 1.0569 − 450 = 468.4 − 450 = 18.4%
Dicas
- The Navy method is surprisingly accurate (within 3-4% of DEXA scans) and requires only a tape measure.