Waist — Measure at the navel level, not the narrowest point. Exhale normally and don't suck in.

Neck — Just below the larynx (Adam's apple), sloping slightly downward at front.

Hip (women) — The widest point of the hips and buttocks, feet together.

The Navy Method has ±3–4% accuracy. For precise measurement, use DEXA scanning or hydrostatic weighing.