Body Fat Calculator

Body Fat, Overweight, and Obesity

What is Body Fat?
Body fat, also known as adipose tissue, is essential for storing energy (in the form of lipids), producing hormones, and providing insulation and cushioning to the body.

There are two types of body fat:

• Essential fat: Vital for life and reproductive health. It makes up about 2–5% of body weight in men and 10–13% in women.

• Storage fat: Found under the skin (subcutaneous) and around internal organs (visceral). This type increases when body fat rises.

A healthy body fat range is usually:

• Men: 8–19%

• Women: 21–33%

While excess body fat can harm your health, having too little fat can also be risky and should be discussed with a healthcare provider.

Understanding Overweight and Obesity

Being overweight or obese means carrying excess body fat, especially storage fat. However, not all overweight individuals have high body fat—muscle mass, bone density, and water also contribute to body weight.

Factors influencing fat accumulation include:

• Genetics

• Diet

• Physical activity

• Hormonal changes (e.g., after age 40 or menopause)

Fat storage patterns vary:

• Men: Fat tends to build up around the stomach.

• Women: Fat may collect in the hips and thighs.

Health Risks of Excess Body Fat

According to the World Health Organization (WHO), obesity is one of the leading preventable causes of death. In the U.S., 36.5% of adults are obese, contributing to:

• Lower quality of life

• Mental health issues

• Sleep apnea

• Increased risk of:

  • Heart disease

  • Stroke

  • Certain cancers

  • Type 2 diabetes

Visceral fat, in particular, can:

• Disrupt hormone function

• Increase LDL (bad) cholesterol

• Decrease HDL (good) cholesterol

• Lead to insulin resistance and high blood sugar

These issues significantly raise the risk of serious health conditions.

How to Measure Body Fat Percentage

1. U.S. Navy Method

This method uses specific body measurements:

For Men:

• Waist: Measured at the navel

• Neck: Below the larynx

For Women:

• Waist: Narrowest point

• Neck: Below the larynx

• Hips: Widest point

Formulas (Estimated Only):

Men:

• USC (inches):
  BFP = 86.010 × log10(waist - neck) - 70.041 × log10(height) + 36.76

• Metric (cm):
  BFP = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450

Women:

• USC (inches):
  BFP = 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387

• Metric (cm):
  BFP = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450

2. Fat Mass and Lean Mass

• Fat Mass (FM): FM = BFP × Weight

• Lean Mass (LM): LM = Weight - FM

3. BMI-Based Body Fat Estimation

If you know your BMI, you can use the following formulas:

Adult Males:
BFP = 1.20 × BMI + 0.23 × Age - 16.2

Adult Females:
BFP = 1.20 × BMI + 0.23 × Age - 5.4

Boys (under 18):
BFP = 1.51 × BMI - 0.70 × Age - 2.2

Girls (under 18):
BFP = 1.51 × BMI - 0.70 × Age + 1.4

Note: These formulas are estimates and not as precise as tools like bioelectric impedance analysis or hydrostatic testing.

Related Calculators
BMI Calculator, BMR Calculator, Calorie Calculator

External Resources:
Body Fat Calculator on Calculator.net