Body Fat Calculator

Estimate your body fat percentage from tape-measure girths (the U.S. Navy method) or from your BMI. Everything runs in your browser — nothing is uploaded.

Body fat—
Category—
Fat mass—
Lean mass—

How to measure body fat with a tape

The U.S. Navy method estimates body fat from a few girth measurements and your height, using a formula developed by the Navy (Hodgdon & Beckett) as a field-friendly alternative to skinfold calipers or a DEXA scan. Stand relaxed and use a flexible tape, snug against the skin but not compressing it. Measure your neck just below the larynx (Adam's apple), sloping slightly downward at the front. Measure your waist at the navel for men, or at the narrowest point of the torso for women. Women also measure hips at the widest point around the buttocks — the men's formula does not use hips, which is why that field hides when Sex is set to Male. Enter your height, and the calculator applies the Navy formula automatically as you type.

Body fat vs BMI

BMI compares your weight to the square of your height and doesn't distinguish muscle from fat, so a muscular person and a person carrying extra fat can land on the same BMI. Body-fat percentage instead estimates what fraction of your weight is actually fat versus lean tissue (muscle, bone, organs and water), which is why it's a better read on body composition. If you want your BMI value itself — the figure this calculator's BMI method is built on — use the BMI Calculator.

Healthy body fat ranges

Using the American Council on Exercise categories that this calculator's results are tinted by: for men, essential fat is roughly 2 to 5%, athletes 6 to 13%, fitness 14 to 17%, average (acceptable) 18 to 24%, and 25% or higher is classed obese. For women, essential fat is roughly 10 to 13%, athletes 14 to 20%, fitness 21 to 24%, average (acceptable) 25 to 31%, and 32% or higher is classed obese. Women carry more essential fat than men by design, which is why the ranges differ by sex rather than sharing one scale.

Frequently Asked Questions

How accurate is the Navy body fat method?
The U.S. Navy method typically comes within about 3 to 4 percentage points of a DEXA scan for most people, which is good enough to track progress over time. Accuracy depends on measuring the same way each time — a snug but not tight tape, at the same spots, without pulling the tape in.
Should I use the tape method or the BMI method?
Use the tape (Navy) method if you can measure your neck and waist accurately — it looks at actual body girths, so it is the more reliable of the two. The BMI method is a fallback for when you only have your height and weight, since BMI on its own cannot tell muscle from fat.
Why does the calculator ask for hips only for women?
The Navy formula for women includes a hip measurement because female fat distribution is not captured accurately by neck and waist alone. The men's formula only needs neck, waist and height, so the hips field is hidden when Sex is set to Male.
What is a healthy body fat percentage?
Using the American Council on Exercise ranges, a healthy or acceptable body fat percentage is roughly 18 to 24 percent for men and 25 to 31 percent for women, with lower ranges for athletes and higher ranges falling into the obese category. Healthy ranges shift with age and individual body type, so treat this as a general guide rather than a target.

Related health tools

BMI Calculator

Calculate body mass index in metric or imperial units, with category ranges.

Health

→

Sleep Calculator

Find the best bedtime or wake-up time based on 90-minute sleep cycles.

Health

→

Body Measurement Tracker

Log body measurements over time, chart progress, and set goals.

Health

→