Skinfold calipers estimate body fat by measuring subcutaneous fat thickness at standard sites. Done consistently, they track change well.
3-site (Jackson-Pollock): chest/abdomen/thigh (men), triceps/suprailiac/thigh (women). Fast and reliable.
7-site adds precision but the extra sites mostly matter for lean athletes.
Same tester, same time of day, same side of body, same hydration. Trends beat single readings.
Prefer a no-caliper method? Try Navy tape.
Army-Navy Body Fat Calculator →
BMI can label muscular athletes as overweight or obese. Here's when BMI misses the mark and what to use instead.
The clearest waist guideline for women, based on the NHS and Ashwell Waist-to-Height ratio — no charts, just one rule.
How age changes your healthy weight range, and the simple WHO/CDC formula that answers "how much should I weigh?".