Body Fat Calculator

Free body fat percentage calculator using the US Navy method and BMI-based formula. Enter your measurements to get body fat %, fat mass, lean mass, and body fat category. Supports both imperial and metric units with visual category charts.

Biological Sex

Age (years)

Weight (lbs)

Height (ft & in)

Body Measurements (for US Navy Method)

Measure at the widest/narrowest point. Leave blank to use BMI-based estimate only.

Neck Circumference (inches)

Waist Circumference (inches)

Enter your age, weight, and height to estimate body fat using the BMI method. Add circumference measurements for a more accurate US Navy Method calculation.

Body Fat Categories (Male)

Essential Fat2% - 5%

Minimum fat needed for basic physiological function. Dangerously low for sustained periods.

Athletes6% - 13%

Typical range for competitive athletes. Very lean with visible muscle definition.

Fitness14% - 17%

Fit and healthy range. Good muscle definition with a lean, toned appearance.

Acceptable18% - 24%

Average range for the general population. Healthy but with room for improvement.

Obese25%+

Excess body fat associated with increased health risks. Consult a healthcare professional.

Healthy Body Fat Ranges by Age

Age Range	Male (Healthy)	Female (Healthy)
20-29	7-17%	16-24%
30-39	12-21%	17-25%
40-49	14-23%	19-28%
50-59	16-24%	22-31%
60+	17-25%	22-33%

Disclaimer

This calculator provides estimates based on mathematical formulas. The US Navy Method and BMI-based method are screening tools, not diagnostic measures. Accuracy varies based on individual body composition.

This is not medical advice. Body fat distribution, muscle mass, bone density, and other factors affect health outcomes beyond what these formulas can measure. For precise body fat measurement, consider methods such as DEXA scans, hydrostatic weighing, or professional calipers.

Always consult a healthcare professional before making significant changes to your diet or exercise routine.

How to Use Body Fat Calculator

1Select your gender and enter your age.
2Enter height, weight, neck, and waist measurements.
3For women, also enter hip circumference.
4View body fat %, category, and body composition breakdown.

Frequently Asked Questions

How accurate is the body fat calculator?▾

The US Navy method is accurate to within 3-4% for most people. For more precise measurements, consider DEXA scans or hydrostatic weighing.

What is a healthy body fat percentage?▾

For men: 10-20% is fitness range, 18-25% is acceptable. For women: 18-28% is fitness range, 25-31% is acceptable. Essential fat is 2-5% for men and 10-13% for women.

How do I measure my waist and neck?▾

Measure your waist at the narrowest point (usually at the navel). Measure your neck just below the larynx (Adam's apple). Keep the tape level and snug but not tight.

About Body Fat Calculator

NexTool's Body Fat Calculator is completely free to use with no sign-up required. Your data is processed directly in your browser and never sent to our servers, ensuring complete privacy and instant results.