Body Fat Calculator: Estimate Body Fat % (U.S. Navy Method)

How the U.S. Navy Circumference Method Works

Developed by researchers Hodgdon and Beckett in 1984 at the Naval Health Research Center, the U.S. Navy Body Fat Formula provides a standardized, accessible alternative to expensive hydrostatic weighing or dual-energy X-ray absorptiometry (DEXA) scans.

The method uses logarithmic relationships between circumference measurements—accounting for height, neck, waist, and (in females) hip dimensions—to estimate body density. From body density, relative body fat percentage is derived via the Siri or Brozek equations.

ACE Body Fat Reference Norms

Tips for Maximizing Measurement Precision

• Use a Non-Stretching Tape: Cloth or vinyl tape can stretch over time, producing artificially low readings. Use a fiberglass or tension-regulated body tape measure.
• Measure at the Same Time of Day: Take measurements in the morning before eating or drinking to minimize gastrointestinal bloating.
• Relax the Abdomen: Do not suck in or puff out the stomach; breathe out gently to normal functional residual capacity before recording.
• Keep the Tape Level: Ensure the measuring tape remains strictly horizontal and parallel to the floor around the entire torso.