BMI Calculator — Free Online Tool

Find out your Body Mass Index instantly. Move the sliders, see your result update live, and check where you land on the scale.

24.2

kg/m² — Body Mass Index

Normal weight

Healthy range

1418.5253040

Underweight Normal Overweight Obese

Instant results — no waiting

No sign-up needed

Free forever

How it works

1Set your height with the slider or by typing the exact value in cm.

2Set your weight in kg — the result updates instantly as you move.

3Read your result — BMI value, category and position on the visual scale.

Frequently asked questions

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². For example, a person weighing 70 kg at 170 cm (1.70 m) has a BMI of 70 ÷ (1.70 × 1.70) ≈ 24.2.

What do the BMI categories mean?

The standard WHO ranges are: Underweight below 18.5, Normal weight 18.5–24.9, Overweight 25–29.9, and Obese at 30 or above. These ranges apply to adults.

Is BMI a reliable health measure?

BMI is only a rough screening guide, not a diagnosis. It doesn't distinguish muscle from fat, and it can mislead for athletes, children, pregnant women and older adults. Think of it as a quick starting point — for real health advice, talk to a doctor or a qualified nutritionist. This tool is not medical advice.

BMI = weight (kg) ÷ height (m)² · WHO adult categories · 100% local — nothing leaves your device.