Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy formula. Includes body fat category, lean mass, ideal range, and a full health dashboard with BMI, BMR, and daily calories.
What is Body Fat Percentage?
Body fat percentage is the share of your body weight made up of fat. Unlike weight or BMI alone, it distinguishes fat from lean tissue, making it a more meaningful measure of overall fitness and health.
How to Use the Body Fat Calculator
Select your gender and enter your age, height, and weight. Measure your waist and neck (plus hips for women) with a tape measure, enter the values, and get your body fat percentage along with a full health dashboard.
U.S. Navy Formula Explained
Men:
495 ÷ (1.0324 − 0.19077·log₁₀(waist − neck) + 0.15456·log₁₀(height)) − 450
Women:
495 ÷ (1.29579 − 0.35004·log₁₀(waist + hip − neck) + 0.221·log₁₀(height)) − 450
Example Calculation
Fitness range
What This Calculator Shows
Combine strength training with cardio to preserve lean mass
Maintain a moderate calorie deficit rather than crash dieting
Prioritise protein to protect muscle while losing fat
Stay consistent — body composition changes gradually
Get enough sleep and manage stress to support fat loss
Frequently Asked Questions
Body fat percentage is the proportion of your total weight that is fat. It is a better indicator of fitness than weight alone because it separates fat mass from lean muscle, bone, and water.
The U.S. Navy method estimates body fat from height and circumference measurements. It is convenient and reasonably accurate for most people, typically within a few percent of methods like DEXA.
The female formula includes hip circumference because fat distribution differs between sexes. Including the hip improves the accuracy of the estimate for women.
Healthy ranges depend on age and gender. For men it is roughly 10–20%, and for women roughly 18–28%. The calculator shows the ideal range for your specific profile.
BMR is the calories your body burns at complete rest. TDEE is your total daily energy expenditure including activity, which is what you use for maintenance calorie targets.