Body Fat Calculator

Accuracy

Scientifically Validated

Utilizes the U.S. Navy body fat formula—trusted for its balance of reliability and convenience. Track meaningful changes, not just weight.

Clarity

Personalized Insights

Clear feedback on your body fat category, plus visual dial feedback and tailored next steps for any result.

Security

Your Data Stays Private

Calculations run entirely in your browser. No personal information or measurements are ever stored or shared.

Flexibility

All Ages & Body Types

Works for men, women, athletes, and varying ages—offering a fairer assessment than BMI alone.

Understanding Your Body Fat Percentage

Body fat percentage is the ratio of total fat mass to total body mass, expressed as a percentage. Unlike BMI, which only considers height and weight, body fat percentage distinguishes between fat and lean tissue, providing a direct measure of body composition.

Why Estimate Body Fat?

Knowing your body fat percentage gives more context than weight alone. Two people may weigh the same and have vastly different fitness profiles; one may have high muscle and low fat, while another carries more fat tissue. Health professionals often use body fat estimates to set realistic goals and monitor metabolic health.

Track progress during weight loss or muscle-building programs
Understand health risks associated with high or low body fat
Set athletic, aesthetic, or clinical goals

How Is Body Fat Calculated Online?

This calculator uses the U.S. Navy circumference method, which is recognized for its strong balance of practicality and accuracy. You input your height, sex, and circumferences for neck, waist, and (for women) hip. The formula then applies logarithms to these values to estimate fat mass percentage.

While professional measurements such as DEXA scans or hydrostatic weighing are more accurate, they require specialized equipment and are costly. The online method is ideal for regular tracking and spotting trends over time.

Healthy Body Fat Ranges

Category	Men (%)	Women (%)
Essential Fat	2 - 5	10 - 13
Athletes	6 - 13	14 - 20
Fitness	14 - 17	21 - 24
Average	18 - 24	25 - 31
Obese	25+	32+

For more information on healthy weight and BMI, see our healthy BMI and normal BMI guides.

Limitations and Practical Tips

Measurements must be consistent—always use the same tape measure and method.
The formula is less accurate for very athletic or very overweight individuals.
Track trends over time rather than fixating on a single number.
Body fat is only one part of health—pair this with fitness, diet, and medical advice.

To compare BMI and its limitations, check our BMI formula and how to calculate BMI resources.

Why Not Just Use BMI?

Body fat measurement improves upon BMI by distinguishing between muscle and fat. For example, a bodybuilder may have a "high BMI" but low fat percentage. Conversely, someone with a "normal" BMI may still carry excessive fat. Use both tools in tandem for a holistic view of your health.

What's Next?

Use the calculator above to get your estimate and compare it with healthy ranges. For deeper insight into your fitness or if you have specific medical concerns, consult with a trusted healthcare provider.

Body Fat Calculator FAQ

How accurate is an online body fat calculator?

Online body fat calculators use formulas based on population averages and body measurements. While they provide a useful estimate, they cannot match the accuracy of professional methods like DEXA scans or hydrostatic weighing. Still, they are convenient for tracking trends over time.

Which body measurements do I need to use this calculator?

You will need your height, weight, neck circumference, and waist circumference. If you are female, hip circumference is also required for accuracy. All measurements should be in centimeters or inches, but remain consistent.

What is a healthy body fat percentage?

Healthy body fat percentage varies by age and sex. Generally, 10-22% is considered healthy for men, and 18-30% for women. For more detail, see our healthy BMI and body fat guidelines.

Is body fat percentage better than BMI?

Body fat percentage provides a more direct measure of body composition than BMI, which only considers height and weight. Body fat metrics distinguish between fat and lean mass, making them more informative for health and fitness.

Can I reduce my body fat percentage quickly?

Sustainable body fat reduction is gradual—aim for 0.5 to 1% per month with a combination of diet, exercise, and lifestyle changes. Rapid loss methods are rarely healthy or lasting.