About this calculator

BMI = weight (kg) / height (m)². Under 18.5 = underweight, 18.5–24.9 = healthy, 25–29.9 = overweight, 30+ = obese. BMI is a population-level screen, not a diagnosis.

How it works

Enter your weight and height. The result updates as you type, using the formula shown below. Nothing you enter is stored.

Limits

Population formulas give estimates, not a medical diagnosis. Speak to a doctor before making big changes.

Who it's for

People tracking training, weight or nutrition goals.

Formula: BMI = kg / m²

Frequently asked questions

What does the BMI Calculator do?

Calculate your Body Mass Index from height and weight. BMI = weight (kg) / height (m)². Under 18.5 = underweight, 18.5–24.9 = healthy, 25–29.9 = overweight, 30+ = obese. BMI is a population-level screen, not a diagnosis.

Is the BMI Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the BMI Calculator?

Results are calculated in real time using the formula BMI = kg / m². Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified fitness & health professional before committing to a purchase or a job.

What inputs does the BMI Calculator need?

Enter values for: Weight, Height. Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the BMI Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.