Free Body Fat Calculator Online
Calculate body fat percentage, lean body mass, fat mass, BMI, BMR, healthy body fat category, and fitness estimates with this free body fat calculator.
📏 Body Fat Calculator
Live Body Composition EstimateBody Fat Inputs
Left SideBody Fat Results
Right SideBody Composition Pie Chart
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Body fat formulas are estimates and can vary by measurement accuracy.
Measure the same way each time if tracking changes over time.
Body composition is only one part of overall health and fitness.
What Is a Body Fat Calculator?
A body fat calculator estimates body fat percentage using body measurements such as height, weight, neck, waist, hip, age, and gender. It can also estimate fat mass, lean body mass, BMI, BMR, and general body fat category.
This free online body fat percentage calculator is useful for fitness tracking, body composition estimates, nutrition planning, and understanding changes over time. It uses a measurement-based formula inspired by the U.S. Navy method and provides general estimates only.
Body Fat Percentage Calculator
Estimate body fat percentage from height, neck, waist, and hip measurements.
Lean Body Mass Calculator
Estimate lean mass by subtracting estimated fat mass from total body weight.
Fat Mass Calculator
Estimate how much of total body weight is fat mass based on percentage.
BMI and BMR Estimate
Review BMI, BMI category, and estimated basal metabolic rate.
How Body Fat Estimation Works
Body fat estimation formulas use body measurements to approximate body composition. This calculator uses different measurement relationships for male and female estimates. Because tape measurement placement and posture can affect results, the estimate should be used as a general guide.
Body Fat Calculator Formula
The calculator converts measurements to inches for the formula, estimates body fat percentage, and then calculates fat mass, lean body mass, BMI, and BMR.
Body Fat Percentage vs BMI
BMI compares weight with height, while body fat percentage estimates the share of body weight that is fat mass. BMI is simple and fast, but it does not directly measure body composition. Body fat percentage can add more context, but it is still an estimate unless measured with clinical tools.
Body Fat Calculator Examples
Use the same measurement method over time to compare changes.
Estimate lean body mass from total weight and body fat percentage.
Compare body fat estimate with BMI for a broader view.
Benefits of Using a Body Fat Calculator
Estimate fat mass and lean mass instead of weight alone.
Track measurement-based changes over time with consistent inputs.
Use estimates with calorie, BMI, and fitness calculators for planning.
Measurement Tips
- Measure gently with a flexible tape without pulling too tight.
- Keep the tape level and measure the same location each time.
- Use the calculator as a general estimate, not a diagnosis.
- For personal health concerns, use guidance from a qualified professional.
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Frequently Asked Questions
Is this body fat calculator free?
Yes. You can estimate body fat percentage, fat mass, lean body mass, BMI, and BMR for free.
How does this body fat calculator work?
It uses height, weight, neck, waist, hip, age, and gender to estimate body fat percentage and body composition.
Is body fat percentage the same as BMI?
No. BMI compares weight and height, while body fat percentage estimates how much body weight is fat mass.
What is lean body mass?
Lean body mass is estimated body weight that is not fat mass, including muscle, bone, water, and organs.
What is fat mass?
Fat mass is the estimated amount of body weight represented by fat tissue.
Are body fat calculator results exact?
No. They are estimates and can vary with measurement accuracy and formula limits.
Can I use metric and imperial units?
Yes. You can switch between metric and imperial units in the calculator.
Is this medical advice?
No. This calculator provides general estimates only and is not medical advice.