.webp)
Estimate body fat from the numbers you enter
Choose a method, enter age, height, and weight—and tape measures for Navy. This body fat calculator shows an on-page report you can read, copy, or download. Home estimate only, not a lab measurement.
Estimate disclaimer
This body fat calculator applies published estimate formulas to the numbers you type. Results are approximate, change with method, posture, tape height, and weighing conditions, and are not a medical assessment or training prescription. Category bands are teaching labels from common charts, not a diagnosis. Entertainment and reference only—if a result is unhelpful, close the page.
Estimate body fat percentage from height, weight, and tapeHome formulas with a multi-metric report
Enter age, height, and weight—or add neck, waist, and hip for the Navy method. This body fat calculator runs a published estimate and shows body fat %, fat mass, lean mass, a reference midpoint, BMI, and rough BMR/RMR on the same page. Read the report under the form, copy the text, or download an image if you want a private record. It is an estimate from your inputs, not a lab scan.
More than a lone percentage
The report lists body fat % beside fat mass, lean mass, BMI, an age-and-sex reference midpoint, and rough resting-energy figures. One entry, several related numbers—so a single percent is less easy to misread in isolation.
Report appears under the form
After you calculate, the card below the inputs is the full report: band label, headline percentage, supporting metrics, and which method ran. Nothing to unlock on another screen.
Optional download of that report
Save an image of the result if you want to compare measurement days later. Skip the download if you do not need a file.
Three ways to estimate from what you have
ADA (BMI + age), US Navy (circumferences), or a BMI-based estimate. Pick based on whether you have a tape. None replaces DEXA or clinical body-composition testing; small gaps between methods are normal.
How to calculate body fat percentage at home
You estimate body fat percentage by feeding a published formula the measurements it asks for. “Body fat ratio” in everyday talk usually means that percentage: estimated fat mass as a share of total weight. It is not BMI (also shown on the report) and not a waist-to-hip quotient.
Typical uses
- Get a percentage from height and weight when you do not have a tape
- Add neck, waist, and (if needed) hip for a circumference-based Navy estimate
- See fat mass and lean mass next to the percentage for a clearer picture of the same math
What it is not
- Not a substitute for DEXA, Bod Pod, hydrostatic weighing, or skinfold protocols run by a trained tester
- Not a diagnosis of obesity, malnutrition, or metabolic disease
- Not advice on diet, training, or medication—talk to a qualified professional for health decisions
How to measure body fat inputs
You measure scale and tape values; the calculator estimates percentage from those. Stand upright, breathe normally, keep the tape level and snug—not digging into soft tissue. Use one unit system for every field.
Height, weight, then Navy landmarks if needed
Weigh at a consistent time when you can. Height without shoes. For US Navy: neck just below the larynx; waist at the navel for men, or the narrowest torso point / mid-rib-to-hip if clearer; hip (female setting) at the fullest seat, tape parallel to the floor. Note the numbers before you type. No tape? Use ADA or the BMI-based method instead of Navy.
Method, sex setting, units, calculate
Choose ADA / BMI+age, US Navy, or BMI-based. Female or male changes formula constants and the teaching bands on this page. Enter age and the required fields, then submit.
Read the metrics under the form
The result card shows percentage, band, masses, reference midpoint, BMI, and energy estimates. That is your report. Download an image only if a saved copy is useful.
How do you calculate fat percentage in your body?
Published formulas, not a fat scale
Consumer formulas use BMI and age (Deurenberg-style / ADA), logarithms of circumferences (US Navy), or another BMI-based path. Each returns a percentage from typed measurements—arithmetic, not imaging or density weighing.
Percentage equals fat mass ÷ weight
Body fat % is estimated fat mass divided by total weight. Listing fat mass and lean mass beside the % makes that definition visible. Band labels are chart shorthand for teaching ranges, not clinical diagnoses.
Why method A and method B differ
Tape height, hydration, time of day, and formula choice all move the estimate. A couple of percentage points between Navy and BMI-based results is common. Re-measure carefully before treating a swing as a real change.
Body fat percentage calculator — questions
Q1.How accurate is a home body fat calculator?
It is only as good as your measurements and the formula’s assumptions. Expect a rough estimate. Lab methods (DEXA, densitometry) are more direct. Use this for orientation, not medical decisions.
Q2.Where is the report after I calculate?
On this page, under the form. The result card holds percentage, band, masses, BMI, and energy figures. Download is optional for a saved image.
Q3.Body fat % vs BMI—what is the difference?
Body fat % estimates how much of your weight is fat. BMI is weight relative to height squared. This report can show both; they answer different questions and can disagree.
Q4.Which method should I use?
Have a careful tape for neck, waist, and (when asked) hip? Prefer Navy. Only age, height, and weight? Use ADA or the BMI-based option. Trying two methods is fine—expect small gaps.
Q5.What do “reference mid” and “vs reference” mean?
They are teaching midpoints by age and sex from common charts, plus how far this estimate sits from that midpoint. Optional context—not a required goal or a diagnosis.
Estimates only—read the numbers, then stop
When the run finishes, the panel under the form is the report: percentage, supporting metrics, and method used. Download a copy only if comparing measurement days helps you. This tool does not promise fat-loss outcomes, training plans, or clinical certainty from a home formula.
Results are entertainment and reference estimates. Category bands are chart labels, not medical grades. If a number is unhelpful, close the page and leave the calculator for another time.