Body Fat Calculator
Want a more accurate picture of your health than a simple scale can provide? Our free Body Fat Calculator estimates your body fat percentage using simple tape measurements.
Body Fat Calculator (Navy Method)
What is the Body Fat Calculator - Estimate Body Fat Percentage?
The Body Fat Calculator is a health tracking utility that estimates the percentage of your total body mass that consists of fat tissue. It uses the widely accepted U.S. Navy tape measure method.
How to use the Body Fat Calculator - Estimate Body Fat Percentage
- Select your biological sex.
- Enter your height and neck circumference.
- Enter your waist circumference (at the navel).
- For females, also enter your hip circumference (at the widest point).
- The tool calculates your estimated body fat percentage.
Example
A man with a 100cm waist and a 40cm neck: The algorithm factors the ratio between these measurements and his height, estimating his body fat at roughly 22%.
Understanding Your Results
The percentage represents how much of you is fat vs lean mass (muscle, bone, water). Lower percentages generally indicate a leaner physique, though extremely low percentages can be dangerous.
Common Use Cases
- Fitness Tracking: Measuring real progress when the scale isn't moving because you are simultaneously losing fat and gaining muscle.
- Military/Police Testing: Verifying that an applicant meets strict maximum body fat requirements.
- Dieting: Ensuring that the weight you are losing is actually fat and not vital muscle mass.
How it Works
The tool uses complex logarithmic equations developed by the U.S. Navy. It compares the circumference of areas that typically store fat (waist, hips) against areas that don't (neck) relative to overall height to estimate body composition.
Tips & Accuracy Notes
- •Tape measurements must be taken flush against the skin, but not pulled tight enough to compress the skin.
- •This method is an estimate (usually within 3-4% accuracy). For exact measurements, you would need a DEXA scan or hydrostatic weighing.
Frequently Asked Questions
What is a healthy body fat percentage?
It varies by gender and age. Generally, for men, 10-20% is healthy, while above 25% is considered obese. For women, 20-30% is healthy, while above 32% is considered obese.
Why do women need to measure their hips?
Biologically, women naturally store more body fat in the gluteal-femoral region (hips and thighs) for reproductive health, so the formula must account for this.
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Disclaimer: This tool provides an estimate using the U.S. Navy circumferences method. It is not a clinical diagnostic tool.