Two ways to estimate body fat
The US Navy method uses your height with neck and waist measurements (plus hips for women). The BMI-based method (Deurenberg formula) uses your BMI, age and sex, so it needs your weight too. Showing both lets you see how far apart they are. Neither is a medical measurement.
Fat mass, lean mass and categories
If you enter your weight, the calculator splits it into fat mass and lean mass and places your result in a standard category from essential fat to obese. The categories are general guides, not diagnoses. For your daily energy needs use the calorie calculator, and to plan training intensity try the heart rate zones calculator.
This is general information, not medical advice. Speak to a doctor before changing your diet or exercise plan.
Frequently asked questions
How does the US Navy body fat method work?
It uses circumference measurements. For men it uses height, neck and waist; for women it also uses hips. The numbers go into a logarithmic formula developed by the US Navy to estimate body density and then body fat percentage.
How accurate is it?
Tape-measure formulas are usually within about 3–4 percentage points of a DEXA scan for most people, but they can be off for very muscular or very lean people. Measure the same way each time to track change.
Where should I measure?
Neck: just below the larynx. Waist: for men at the navel, for women at the narrowest point. Hips (women): at the widest point. Keep the tape snug but not tight and do not hold your breath in.
What is a healthy body fat percentage?
Using the ACE categories: for men 2–5% is essential fat, 6–13% athletes, 14–17% fitness, 18–24% average and 25% or more obese. For women the bands are 10–13%, 14–20%, 21–24%, 25–31% and 32% or more.
How is this different from BMI?
BMI only compares weight with height and cannot tell muscle from fat. Body fat percentage uses your measurements, so two people with the same BMI can have very different results. See the BMI calculator for the weight-based view.