Heltrum health guide
How to Estimate Body Fat: Measuring Guide
Body fat percentage refers to the proportion of body mass made up of fat. A home tape-measure estimate is not a direct measurement. Heltrum’s free calculator uses the circumference equations often described as the US Navy method.
Estimate body fat →How to take circumference measurements
Step 1
Height
Measure upright, without shoes, in centimeters.
Step 2
Neck
Measure just below the larynx with a snug, not excessively tight tape.
Step 3
Abdomen / waist
For the male equation, measure the abdomen at the navel. For the female equation, measure the natural narrowest waist. Take a reading after a normal relaxed exhalation.
Step 4
Hip
For the female equation, measure at the widest hip circumference. This field is not used in the male equation.
How are BMI and body fat different?
BMI uses height and weight only. The circumference method additionally considers the neck, abdomen/waist and, when applicable, hips. Both are indicators for screening or planning, not definitive assessments of fat distribution or individual health.
Limitations of this method
Measurement location, breathing, tape tension and body shape affect estimates. This calculator is not an official service assessment or a DEXA measurement. Repeated measurements under similar conditions may be more useful for tracking change than judging a single value.
Related free tools
Go beyond one calculation.
Keep measurement trends, photo progress, meals and training records together in Heltrum.
For general information only, not medical diagnosis, treatment or personal healthcare advice. The guide draws on the identified institutional document; no expert review is claimed.