Body Composition

Body fat, lean mass, FFMI and ideal-weight estimates from measurements you can take at home.

• Body Fat Calculator

  Estimate body fat percentage from waist, neck and (for women) hip measurements using the US Navy circumference formula, in cm or inches.

• Lean Body Mass Calculator

  Estimate lean body mass and fat mass from height, weight and sex using the Boer, James or Hume formula, toggled in one calculator.

• FFMI Calculator

  Calculate your fat-free mass index (FFMI) and height-normalized FFMI from weight, height and body fat percentage, with the natural-range context explained.

• Ideal Body Weight Calculator

  Estimate ideal body weight from height and sex using the Devine, Robinson, Miller or Hamwi formula, toggled in one tool, with results in kg and lb.

• Waist-to-Height Ratio Calculator

  Calculate your waist-to-height ratio (WHtR), a simple screening measure some researchers consider a better fit-risk indicator than BMI alone.

• BMI Calculator

  Calculate adult BMI in metric or imperial units, see your WHO weight category, and get the healthy-weight range for your height — with its real limits explained.

• Skinfold Body Fat Calculator

  Estimate body fat percentage from 3-site caliper skinfold measurements using the Jackson-Pollock regression formula and the Siri body-density equation.

• Waist-to-Hip Ratio Calculator

  Calculate your waist-to-hip ratio (WHR) and compare it against the World Health Organization's sex-specific cardiometabolic risk bands.

• Body Shape Index Calculator

  Calculate four published BMI alternatives — A Body Shape Index, Body Roundness Index, Relative Fat Mass and Body Adiposity Index — in one toggleable tool.

• Body Frame Size Calculator

  Estimate whether you have a small, medium or large skeletal frame from your height-to-wrist-circumference ratio, and see how it should adjust ideal-weight estimates.

• Adjusted Body Weight Calculator

  Calculate adjusted body weight from actual weight and Devine ideal weight using the standard 0.4 correction factor, for training-load and planning use.