Use this body-composition measurement as a screening or estimation aid when the required measurements were collected with the method and units stated by the tool.

Waist circumference (cm)

Waist circumference measured in centimeters.

Height (cm)

Standing height measured in centimeters.

Calculate body roundness index from waist circumference and height measured in the same unit. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Body roundness index

The calculated dimensionless body roundness index.

• Population equations and screening indices do not directly diagnose health or measure every body compartment. Hydration, age, sex, ethnicity, athletic build, measurement technique, and the population used to derive an equation can affect interpretation.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Interpret the result with other measurements, trends, medical history, and professional guidance. Use a validated reference method when individual body composition must be measured more directly.

• Bioelectrical Impedance Index Calculator

  Calculate height squared divided by measured electrical resistance; this is an impedance index, not a body-fat estimate.

• Body Mass Index

  Calculate body mass index from weight in kilograms and height in metres.

• Analytical Spike Recovery

  Calculate percent recovery as (measured spiked result − unspiked result)/known spike amount ×100. All three quantities must use the same unit; values outside 0–100% can reveal matrix effects or measurement problems.