BMI Calculator - Body Mass Index (Metric & Imperial)

Calculate Body Mass Index from height and weight - metric (cm/kg) or imperial (ft·in/lb)

🔒 100% in-browser🆓 Free forever⚡ No sign-up
Your BMI
23.5
Healthy weight
BMI ranges (WHO adults): under 18.5 underweight · 18.5–24.9 healthy · 25–29.9 overweight · 30+ obesity. BMI is a screening tool, not a diagnosis - it doesn't distinguish muscle from fat.
Estimates only. Results are generated by generalised formulas from the inputs you provide and are for informational purposes only. They are not financial, tax, legal, medical, or professional advice, and do not account for your individual circumstances, jurisdiction, taxes, fees, or health conditions. Verify important figures with a qualified professional. By using this tool you agree to our Terms & Disclaimer.

How it works

  1. 1
    Pick your units

    Choose metric (cm and kg) or imperial (feet/inches and pounds).

  2. 2
    Enter height and weight

    Type your values in the labeled fields - BMI updates instantly.

  3. 3
    Read the category

    See your BMI value and the World Health Organization classification: underweight, healthy, overweight, or obesity class I/II/III.

About BMI Calculator - Body Mass Index (Metric & Imperial)

Free BMI (Body Mass Index) calculator. Enter your height and weight in metric (cm and kg) or imperial (feet, inches, and pounds) units to instantly see your BMI and the WHO classification: underweight, healthy weight, overweight, or obesity. Includes the full BMI formula and interpretation ranges. Runs entirely in your browser. BMI Calculator - Body Mass Index (Metric & Imperial) on 712 Tools runs entirely inside your browser using modern JavaScript APIs - no server ever sees your data. That means instant results, complete privacy, and no upload limits.

Whether you need to calculate body mass index from height and weight - metric (cm/kg) or imperial (ft·in/lb) for a debugging session, a quick sanity check, or a production incident, this tool is free to use as many times as you need. There are no watermarks, no sign-up, and no ads inside the tool itself.

Frequently asked questions

What is the BMI formula?

Metric: BMI = weight (kg) ÷ height (m)². Imperial: BMI = (weight in lb ÷ height in inches²) × 703.

What are the BMI ranges?

WHO adult ranges: under 18.5 = underweight, 18.5–24.9 = healthy, 25–29.9 = overweight, 30–34.9 = obesity I, 35–39.9 = obesity II, 40+ = obesity III.

Is BMI accurate for everyone?

BMI is a screening tool, not a diagnosis. It doesn't distinguish muscle from fat, so athletes and very muscular people may be classified as overweight even when they are lean. Talk to a healthcare provider for a full assessment.

Is my data uploaded?

No. All calculations run entirely in your browser.

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