Body Fat Calculator
Use this body fat calculator to estimate your body-fat percentage from measurements you can take at home, then save a check you can repeat.
Choose a method that fits what you can measure: height and weight, a tape measure or skinfold calipers. Weight starts in pounds, height in inches and skinfolds in millimeters; other available units are shown on the form.
Choose which estimate leads your results and add other methods if you want to compare them. Repeat the same method and measuring steps for a useful next check.
Use the calculator
Choose a method that matches the measurements you have. Select it to open the fields and follow the instructions shown there.
The first method you select leads the result. Add other methods to compare estimates, or choose “Use as main result” to switch the lead method.
Some methods ask for age and a male or female equation. Weight is required for CUN-BAE; for other methods it is optional and adds estimated fat weight and fat-free weight from the main method.
You can also record a result from another test. It stays separate from the formula estimates.
Which method fits my measurements?
For CUN-BAE, choose the male or female formula and enter age, height and weight. Tape options use different waist locations; skinfold options need calipers and their own site instructions.
Choose a method you can measure consistently. The comparison shows each estimate separately and does not identify which one is closest for you.
How to take your measurements
Follow the field instructions for the exact location. The Navy and RFM waist measurements use different landmarks, so do not substitute one for the other.
Enter skinfold readings in millimeters. Jackson–Pollock uses two readings per site within 1 mm; the calculator uses their mean. Its abdomen site is 2 cm to the right of the navel, following the cited ACSM guide.
Durnin–Womersley uses three readings at each of four different sites. Keep those sites separate from Jackson–Pollock and follow the instructions shown for the selected method.
What your results mean
The main percentage is an estimate from the method you chose, not a direct measurement. Different equations and measurement steps can produce different results.
When you enter weight, estimated fat weight and fat-free weight are calculated from the main method. Fat-free weight includes muscle, bone, organs and water.
A result from another device or test stays separate and is not verified by this calculator.
| Method | Estimate | Procedure |
|---|---|---|
| CUN-BAE (height and weight) | 23.4% | Height, weight and age with the selected male or female equation. |
| U.S. Navy tape | 17.5% | Height, neck and waist; women also measure the widest hip. |
| Relative Fat Mass (RFM) | 22.8% | Height and waist at the top of the right hip bone. |
| Jackson–Pollock 3-site | 13.6% | Three skinfold sites, with two readings within 1 mm at each. |
| Jackson–Pollock 7-site | 13.2% | Seven skinfold sites, with two readings within 1 mm at each. |
| Durnin–Womersley four-site | 18.6% | Four skinfold sites, with three readings at each. |
Make your next check comparable
Use the same method, equation, measurement locations and steps next time. This makes it easier to compare estimates on the same basis.
You can save or copy the check for later. An outside test can be recorded separately as entered; it is not treated as a formula estimate.
Methods and sources
This table shows what each method uses and the age range supported here, so you can choose an option that fits your measurements.
| Method | Age range and study limits | What to measure and how |
|---|---|---|
| CUN-BAE | Developed using general adult data. This calculator supports ages 18–80 and body mass index (BMI) 12.4–72.8 kg/m²; it has not been established here for every population, including athletes. | Age, body mass index, height, weight and the selected male or female equation. |
| U.S. Navy tape | This calculator uses historical 2006 equations for adults aged 18 or older. It does not determine current military eligibility. | Height, neck and the waist location shown; the female equation also uses the widest hip measurement. |
| Relative Fat Mass (RFM) | The original study included ages 20–85; a later validation group included ages 20–69. This calculator supports ages 20–69. | Height and waist measured at the top of the right hip bone, using the selected male or female source equation. |
| Jackson–Pollock 3-site | The source equations cover men aged 18–61 and women aged 18–55. The authors advise caution for women over 40. | Three skinfold sites based on the selected equation, with two readings per site within 1 mm. The abdomen site is 2 cm right of the navel, following the ACSM eighth-edition guide. |
| Jackson–Pollock 7-site | The source equations cover men aged 18–61 and women aged 18–55. The authors advise caution for women over 40. | Seven skinfold sites, with two readings per site within 1 mm. The abdomen site is 2 cm right of the navel, following the ACSM eighth-edition guide. |
| Durnin–Womersley | This calculator supports men aged 18–72 and women aged 18–68, using an equation selected for the entered age. | Four skinfold sites, with three readings per site, following the MEPSCAT 1984 guide. These sites and steps differ from Jackson–Pollock. |
See the source limits
These methods were developed with different people and measurements. Published age ranges describe the study groups; they do not show how closely an estimate will match you.
Sources
- Body fat percentage in adults: a new prediction equation based on anthropometric measurements (2012)
- Assessing Fitness for Military Enlistment: Physical, Medical, and Mental Health Standards (2006)
- Relative Fat Mass (RFM) as a new estimator of whole-body fat percentage (2018)
- Generalized equations for predicting body density of men (1978)
- Generalized equations for predicting body density of women (1980)
- ACSM's Guidelines for Exercise Testing and Prescription, eighth edition, Box 4.2 (2010)
- Body fat assessed from total body density and its estimation from skinfold thickness measurements (1974)
- Anthropometric survey of US Army personnel: methods and summary statistics (1984)
Frequently asked questions
Does the calculator measure my exact body-fat percentage?
No. Each option estimates body fat from its measurements and equation; it is not a direct measurement.
Why can the methods give different results?
They use different equations, study groups, measurement locations and procedures. The comparison cannot tell which estimate is closest for you.
Which method should I choose?
Choose one whose measurements you can take and repeat consistently. The page shows the instructions for each option.
Do I need to enter my weight?
Weight is required for CUN-BAE. For other methods it is optional; when entered, it adds estimated fat and fat-free weight from the main method.
Can I include a result from a scan or device?
Yes. Record its result as entered, with its test type and date. The calculator does not verify it and keeps it separate from formula estimates.