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BMI Calculator — Body Mass Index (Metric & Imperial)

Calculate your BMI in metric or imperial units. See whether you are underweight, normal, overweight or obese — with the official WHO ranges.

BMI Calculator

✨ AI Explainer

What your BMI actually says

Personalised to your numbers. Free 5/day · 25/day signed-in.

About this tool

What BMI tells you

BMI is weight (kg) divided by height (m) squared. The WHO categories are: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese.

What BMI does not tell you

BMI ignores muscle mass. A bodybuilder and a couch potato can both score 28. Use BMI as a rough screen, not a verdict — body fat percentage and waist-to-hip ratio give a fuller picture.

How to use the BMI Calculator

Takes about a minute. No signup, no download, your data stays in your browser.

  1. 1
    Open the tool. Scroll up to the BMI Calculator above — it loads instantly in your browser, no install needed.
  2. 2
    Enter your values. The fields come pre-filled with realistic defaults so you can see how it works — replace them with your own numbers.
  3. 3
    Read the result. The output updates instantly. Copy or share it — nothing is uploaded to a server, everything stays on your device.

Frequently asked questions

Common questions about the BMI Calculator.

Is the BMI Calculator free to use?

Yes. The BMI Calculatoron 7BusyBoss is completely free — no signup, no paywall, no usage cap. We do recommend paid alternatives in a sidebar card, but the core tool stays free.

Do I need to sign up to use the BMI Calculator?

No. The BMI Calculatorworks instantly in your browser — no account needed. Signing in with Google is optional and only unlocks features like saving favorites and higher AI build limits.

Does the BMI Calculator work on mobile?

Yes. Every tool on 7BusyBoss is mobile-responsive and works in any modern browser — Chrome, Safari, Firefox, Edge — on phones, tablets and desktops.

Is my data safe when I use the BMI Calculator?

Yes. The BMI Calculatorruns entirely in your browser — your inputs never leave your device unless the tool explicitly fetches public data (e.g. currency rates). We don't store the values you type.

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