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Health

BMI Calculator

Enter your height and weight to compute Body Mass Index (BMI). Switch between metric or imperial units and view your category and healthy weight range. All calculations run locally in your browser.

Body Mass Index (BMI)
Client-side onlyNo data leaves your browser
Units
Metric • Client-side
Height
cm

Quick adjust: 170 cm

Weight
kg

Quick adjust: 65 kg

Age (optional)

Age isn’t used in BMI math, but some contexts report it.

Sex (optional)

Display only; BMI categories here follow WHO general guidance.

Results

BMI: 22.5Normal
Summary
  • Height: 170 cm
  • Weight: 65 kg
  • BMI: 22.5 (Normal)

BMI = weight(kg) / [height(m)]². For imperial, the formula is 703 × weight(lb) / [height(in)]².

Healthy Weight Range

For a height of 170 cm, a BMI of 18.5–24.9 corresponds to approximately 53.5–72 kg.

Categories (WHO): Underweight < 18.5, Normal 18.5–24.9, Overweight 25–29.9, Obesity ≥ 30.

How to Use the BMI Calculator

This free, client-side BMI Calculator helps you quickly find your Body Mass Index using either metric (cm, kg) or imperial (ft/in, lb) units. No data leaves your browser.

  1. Select your units: Choose Metric (centimeters & kilograms) or Imperial (feet/inches & pounds) from theUnits dropdown.
  2. Enter your height: Type your height in the inputs provided. You can also use the height slider for quick adjustments.
  3. Enter your weight: Provide your current body weight. The weight slider lets you fine-tune fast.
  4. Read your results: The tool instantly shows your BMI value and category (Underweight, Normal, Overweight, or Obesity Classes I–III).
  5. Check your healthy weight range: Based on a BMI of 18.5–24.9, see the estimated range that may be considered “healthy” for your height.
  6. Copy or reset: Use Copy to save your summary or Reset to start over.

Formula & Calculation

  • Metric: BMI = weight(kg) ÷ [height(m)]²
  • Imperial: BMI = 703 × weight(lb) ÷ [height(in)]²
  • Categories (WHO): Underweight < 18.5, Normal 18.5–24.9, Overweight 25–29.9, Obesity ≥ 30

Tips for Accurate Results

  • Measure height without shoes; stand upright against a wall.
  • Weigh yourself at a consistent time of day (e.g., morning).
  • Switch units anytime—values convert automatically between cm/kg and ft/in/lb.
  • Remember BMI is a screening metric; it doesn’t account for muscle mass, body composition, age, or sex differences.

FAQ

What is a healthy BMI?

For most adults, a BMI of 18.5–24.9 is considered “normal.” However, individual health varies—always discuss results with a qualified professional.

Is my data private?

Yes. This calculator runs entirely in your browser (client-side). No inputs are uploaded or stored on a server.

Why does my BMI seem high if I lift?

BMI does not distinguish between fat and lean mass. Athletes or muscular individuals may show a higher BMI despite low body fat.

Disclaimer: BMI is a general indicator, not a diagnosis. For personalized assessment, consult a healthcare professional.