BMI Calculator

Your Body Mass Index, category and healthy weight range — in seconds.

FREE TOOL · WORKS OFFLINE · NO SIGN-UP

Results update instantly as you type.

Your BMI
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Category
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Healthy weight range for your height
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Underweight < 18.5 · Healthy 18.5–24.9 · Overweight 25–29.9 · Obese 30+

📏 How This BMI Calculator Works

  1. 1.Enter your height and weight. US units are the default — feet + inches and pounds. Switch to metric (cm / kg) any time with the toggle.
  2. 2.The formula. BMI = 703 × weight (lb) ÷ height (in)² — or weight (kg) ÷ height (m)² in metric. Your score appears instantly.
  3. 3.Read your category. Under 18.5 is underweight, 18.5–24.9 is healthy, 25–29.9 is overweight, and 30 or higher is obese.
  4. 4.Check the healthy range. The calculator also shows the weight range that would put your height in the healthy BMI zone — a practical target, not just a score.
  5. 5.Remember the limits. BMI is a screening tool, not a diagnosis. Muscle, bone density and age all matter — use it as a starting point, not the full story.

❓ FAQ

What is a healthy BMI?

For most adults, a BMI between 18.5 and 24.9 is classified as healthy (normal weight). Below 18.5 is underweight, 25.0–29.9 is overweight, and 30.0 or above is obese.

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². In US units: BMI = 703 × weight (lb) ÷ height (in)². This calculator handles both automatically.

Is BMI accurate for athletes and muscular people?

BMI doesn't measure body fat directly. Very muscular people can score "overweight" without excess fat, and older adults can score normal with low muscle. A clinician can give you the full picture.

Is this BMI calculator free?

Yes — 100% free, no sign-up. Your height and weight stay in your browser; nothing is uploaded, saved or tracked.