CUN-BAE
Uses BMI, age, and sex based on the Clinica Universidad de Navarra Body Adiposity Estimator equation.
Gomez-Ambrosi et al., Diabetes Care, 2012Free Online Tool
Free Body Fat Calculator
Estimate your body fat using scientifically validated formulas: CUN-BAE, U.S. Navy, BMI, and Jackson-Pollock. Get your body fat category, lean mass, and personalized weight goals.
4 methods
From quick estimates to tape and skinfold workflows
Private by design
Measurements stay in the browser and recent history stays local
Built for comparison
Switch methods and units without losing context
Enter Your Details
Your body measurements stay in your browser. We do not upload or store your height, weight, or circumference inputs on our servers.
Most popular. Uses BMI, age, and sex for a reasonable estimate. Accuracy: ~4.7%
Units:
in
lb
CUN-BAE Method
The Clinica Universidad de Navarra Body Adiposity Estimator uses your BMI, age, and sex to estimate body fat percentage without tape measurements.
Best for: Quick estimates when you only know height, weight, age, and gender.
Accuracy: At-home formula estimates may vary compared with clinical methods. Best used for tracking trends over time.
How to Measure
- 1Weigh yourself in the morning before eating, after using the bathroom.
- 2Measure height without shoes, standing tall against a wall.
- 3Use the same scale each time to reduce variability.
- 4Track measurements weekly at the same time of day.
Frequently Asked Questions
Method Comparison
| Method | Inputs | Accuracy note |
|---|---|---|
| CUN-BAE | Height, weight, age, sex | Formula estimate |
| U.S. Navy | Neck, waist, hip, height | Technique matters |
| BMI | Height, weight, age, sex | Broad estimate |
| Skinfold | 3 skinfold sites + age | Technique matters |
At-home estimates can vary compared with clinical methods. All methods work best for tracking trends over time.
Tips for Consistent Results
- •Measure at the same time of day (morning is best).
- •Use the same method every time — don't compare across methods.
- •Stay hydrated normally; dehydration skews readings.
- •Avoid measuring right after exercise (temporary fluid shifts).
- •Track over weeks, not days — weekly trends matter more than daily noise.
- •Take photos alongside measurements for a visual reference.
Recent calculations
Stored locally on this device only.
Your latest successful results will appear here for quick comparison.
CUN-BAE Method
The Clinica Universidad de Navarra Body Adiposity Estimator uses your BMI, age, and sex to estimate body fat percentage without tape measurements.
Best for: Quick estimates when you only know height, weight, age, and gender.
Accuracy: At-home formula estimates may vary compared with clinical methods. Best used for tracking trends over time.
How to Measure
- 1Weigh yourself in the morning before eating, after using the bathroom.
- 2Measure height without shoes, standing tall against a wall.
- 3Use the same scale each time to reduce variability.
- 4Track measurements weekly at the same time of day.
Frequently Asked Questions
Method Comparison
| Method | Inputs | Accuracy note |
|---|---|---|
| CUN-BAE | Height, weight, age, sex | Formula estimate |
| U.S. Navy | Neck, waist, hip, height | Technique matters |
| BMI | Height, weight, age, sex | Broad estimate |
| Skinfold | 3 skinfold sites + age | Technique matters |
At-home estimates can vary compared with clinical methods. All methods work best for tracking trends over time.
Tips for Consistent Results
- •Measure at the same time of day (morning is best).
- •Use the same method every time — don't compare across methods.
- •Stay hydrated normally; dehydration skews readings.
- •Avoid measuring right after exercise (temporary fluid shifts).
- •Track over weeks, not days — weekly trends matter more than daily noise.
- •Take photos alongside measurements for a visual reference.
Sources & Methodology
MyFatCalc estimates body fat with published equations and established category ranges. Results are formula estimates, so compare trends using the same method and measurement routine.
U.S. Navy
Uses height and circumference measurements derived from the Navy body composition assessment work by Hodgdon and Beckett.
Hodgdon & Beckett, Naval Health Research Center, 1984BMI Body Fat
Estimates body fat from BMI, age, and sex using the Deurenberg adult prediction equation.
Deurenberg et al., British Journal of Nutrition, 1991Jackson-Pollock 3-site
Uses gender-specific three-site skinfold measurements and age with Jackson, Pollock, and Ward body density equations.
Jackson & Pollock, 1978; Jackson, Pollock & Ward, 1980Women's equation sourceACE Categories
Classifies results into Essential Fat, Athletes, Fitness, Average, and Obese ranges using American Council on Exercise reference categories.
American Council on ExerciseLast updated: June 3, 2026
This tool provides estimates for informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Consult a qualified healthcare provider for personalized guidance.
Why Trust MyFatCalc?
Peer-Reviewed Formulas
All calculations are based on published research from the Naval Health Research Center, CUN-BAE study, and ACE standards.
Multiple Methods
Choose from 4 validated methods depending on what measurements you have available.
Private & Free
No account required. All calculations happen in your browser, and measurement inputs are not uploaded to our servers.
Quick Guide
CUN-BAE
Best default. Just height, weight, age, and gender.
U.S. Navy
Most accurate. Needs tape measurements.
BMI
Simplest estimate. Less accurate for muscular people.
Jackson-Pollock
Needs skinfold calipers. Great for home tracking.
Understanding Body Fat Percentage
Body fat percentage is the proportion of your total body weight that is made up of fat tissue. Unlike BMI, which only considers height and weight, body fat percentage gives you a more accurate picture of your body composition.
Why Body Fat Matters
Your body needs some fat to function properly. This is called essential fat. It helps regulate hormones, insulates your body, and protects vital organs. However, excess body fat, especially visceral fat around your organs, is linked to increased risk of heart disease, type 2 diabetes, and other health conditions.
How Accurate Are These Calculators?
Each method has a different margin of error. The U.S. Navy method is generally the most accurate tape-measure approach. The CUN-BAE method offers a good balance of accuracy and convenience. For the most precise measurement, methods like DEXA scans or hydrostatic weighing are required in a clinical setting.
How to Measure Correctly
For Tape Measure Methods
- Use a non-stretchable tape measure
- Measure against bare skin
- Keep tape parallel to the floor
- Do not compress the skin
- Take measurements in the morning
For Skinfold Methods
- Use professional calipers if possible
- Pinch skin and subcutaneous fat, not muscle
- Take 2-3 measurements per site and average
- Measure from the right side of the body
- Have someone help with hard-to-reach areas
Frequently Asked Questions
What is a healthy body fat percentage?
For women, a healthy range is typically 21-31% and for men it's 14-24%. Athletes may be lower, but lower is not automatically healthier for everyone.
Which body fat calculation method is most accurate?
The U.S. Navy method is usually the strongest tape-measure option at home. CUN-BAE is a strong default when you only have height, weight, age, and sex.
Can I have a low body fat percentage but high BMI?
Yes. BMI does not distinguish muscle from fat, so muscular people can show a high BMI while still having a healthy body fat percentage.
How often should I measure my body fat?
Most people get better signal from measuring every 2 to 4 weeks under similar conditions instead of checking daily.
Why do men and women have different healthy ranges?
Women naturally carry more essential fat because of biological and hormonal differences, so the reference ranges are higher than for men.