Our free body fat calculator estimates your body fat percentage using the U.S. Navy body fat formula. This widely-used method requires only a few simple measurements — no expensive equipment needed. Simply measure your height, weight, neck, and waist (and hips for women) and get your estimate in seconds.

Body fat percentage is a more informative health indicator than BMI alone, as it directly reflects the proportion of fat to lean mass in your body. Understanding your body fat percentage helps you set realistic fitness goals, track progress, and assess health risks more accurately than weight alone.

How to Use the Body Fat Calculator

To estimate your body fat percentage, follow these steps:

1. Select your sex and preferred unit system.
2. Enter your height and weight.
3. Measure and enter your neck circumference — measured just below the larynx.
4. Measure and enter your waist circumference — at the navel for men, smallest point for women.
5. Women only: Measure and enter your hip circumference at the widest point.
6. Click Calculate Body Fat to see your percentage, category, fat mass, and lean mass.

When Should You Use a Body Fat Calculator?

Use the body fat calculator as part of a regular fitness assessment to track changes in body composition over time. In particular, it is useful when you are strength training, as muscle gain and fat loss may keep your weight the same while significantly improving your body composition.

Furthermore, tracking body fat percentage rather than just weight gives a more accurate picture of fitness progress. Additionally, use it alongside BMI to get a more complete health assessment — some people with a normal BMI may have a high body fat percentage, and vice versa.

Body Fat Percentage Guidelines for Men and Women

Here are the general body fat percentage categories for men and women:

• Men — Essential fat: 2–5% | Athletic: 6–13% | Fitness: 14–17% | Average: 18–24% | Obese: 25%+
• Women — Essential fat: 10–13% | Athletic: 14–20% | Fitness: 21–24% | Average: 25–31% | Obese: 32%+
• Measure consistently — Always measure at the same time of day for the most consistent results.
• The Navy formula has ±3–4% accuracy — It is a good estimate but not as precise as DEXA scans.

Frequently Asked Questions About the Body Fat Calculator

What is a healthy body fat percentage?

For men, 14–17% is generally considered the fitness range. For women, 21–24% is the fitness range. Athletes may have significantly lower body fat, but very low levels can be unhealthy.

How accurate is the Navy body fat formula?

The US Navy formula has an accuracy of approximately ±3–4% compared to DEXA scans. It is a reliable estimate for most people, though individuals with unusual fat distribution may get less accurate results.

Related Calculators

Furthermore, you might find these related tools useful: BMI Calculator — Ideal Weight Calculator — BMR Calculator — Calorie Calculator

Disclaimer: Body fat estimates are approximate. Consult a healthcare professional for a complete body composition assessment.