Tool workspace

BMI Calculator

Estimate adult BMI with clear category ranges and an easy visual indicator.

Your calculation is performed locally in your browser.

Results are estimates for informational purposes and should not be treated as financial, tax, or investment advice.

Unit system

Enter values and click Calculate.

Use in code

BMI is weight divided by squared height after unit normalization.

Calculate BMI

TypeScript

Primary API

weightKg / (heightM * heightM)

Normalizes units before applying the BMI formula.

Built-in API
function bmi(weightKg: number, heightCm: number) {
  const heightM = heightCm / 100;
  return weightKg / (heightM * heightM);
}

How this calculator works

  1. Select metric or imperial units.
  2. Enter your height and weight.
  3. Review your BMI value, category, and range marker.

Use cases

  • Quickly estimate adult BMI for wellness tracking.
  • Compare metric and imperial measurements in one place.

Rules and regulations

  • Adult BMI categories use standard thresholds: underweight (<18.5), healthy weight (18.5-24.9), overweight (25.0-29.9), obesity (>=30.0).

Source: CDC adult BMI categories

Limitations and assumptions

  • BMI is a screening measure and is not a diagnosis.
  • This tool is for adults and does not provide pediatric BMI interpretation.

FAQ

Is this an official medical diagnosis?

No. BMI is a screening indicator and not a medical diagnosis.

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