BMI Calculator
Check your Body Mass Index in seconds. Enter your height and weight — everything calculates instantly in your browser, privately and free.
Enter your height and weight above to see your BMI.
How it works
- Pick your units — metric or imperial, whichever you think in.
- Enter height and weight — the result updates live as you type.
- Read your result — your BMI plus the healthy weight range for your height.
What is BMI?
Body Mass Index is a simple screening measure: your weight in kilograms divided by your height in metres squared. It puts you in one of four bands — underweight (below 18.5), healthy (18.5–24.9), overweight (25–29.9) or obese (30 and above).
BMI is a useful rough guide, not a diagnosis. It can’t tell muscle from fat, so very muscular people, pregnant women and older adults should treat it as one signal among many — your doctor sees the full picture.
Frequently asked questions
Is this BMI calculator accurate?
Yes — it uses the standard WHO BMI formula with full precision, calculated instantly in your browser.
Is my data private?
Completely. Nothing you type ever leaves your device; there is no server involved.
What’s a healthy BMI?
Between 18.5 and 24.9. The calculator also shows the healthy weight range in kg or lbs for your exact height.
Does BMI work for athletes?
Not always — muscle is denser than fat, so muscular people can score “overweight” while being very fit. Use it alongside waist measurement and how you feel.