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Body Fat Calculator

Estimate your body fat percentage using the US Navy circumference method. More practical than skinfold calipers — only a measuring tape needed.

Your Measurements
Gender
Unit
Height175 cm
cm
50250
Waist (at navel)85 cm
cm
30200
Neck (below larynx)38 cm
cm
2080
Your Result

Fill in the details and
your result appears here.

Body Fat %
Category
Fat Mass
Lean Mass
Healthy Range (your age)
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Did You Know?
Waist measurement matters most
For health risk, waist circumference alone is highly predictive. Men above 40 inches (102cm) and women above 35 inches (88cm) are at significantly higher risk of metabolic disease regardless of overall body fat percentage.

How to use this calculator

1

Measure correctly

Waist: at the navel level. Neck: just below the larynx (Adam's apple). Hip (women): widest point around the glutes.

2

Select gender and units

Women need hip measurement — the field appears automatically.

3

Enter measurements

Use the same unit throughout. Result appears instantly.

The formula explained

Uses the US Navy circumference method:

Male: BF% = 495 ÷ (1.0324 − 0.19077×log10(waist−neck) + 0.15456×log10(height)) − 450
Female: adds hip measurement to the formula

All measurements in centimetres. This method is used by the US military for fitness assessments and is accurate to ±3–4% for most people.

Frequently Asked Questions

How accurate is this body fat calculator?

The US Navy method is accurate to ±3–4% for most people. It is less accurate at very low or very high body fat levels. DEXA scan is the gold standard but requires specialist equipment.

What is a healthy body fat percentage?

Men: 18–25% is average, 14–18% is fitness level. Women: 25–32% is average, 21–25% is fitness. Athletes are typically 6–13% (men) and 14–21% (women).

Why do men and women have different ranges?

Women require more essential fat for hormonal function and reproductive health. The minimum essential fat is ~3% for men and ~12% for women.

Where do I measure waist circumference?

At the navel — not the narrowest point. Keep the tape horizontal and snug but not tight. Exhale normally before measuring.

What body fat percentage is healthy?

For men: Essential fat 2-5%, Athletic 6-13%, Fitness 14-17%, Acceptable 18-24%, Obese 25%+. For women: Essential 10-13%, Athletic 14-20%, Fitness 21-24%, Acceptable 25-31%, Obese 32%+.

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