BMI Calculator
Live Body Mass Index with premium result card and health gauge.
Your details
AI insight
How to use
- Enter weight in kg and height in cm.
- Click Calculate BMI.
- Read BMI number and health category.
How this tool works
Body Mass Index (BMI) is a screening number from height and weight. It is widely used to classify underweight, normal, overweight and obese ranges in adults, but it does not measure body fat directly.
Formula
BMI = weight (kg) ÷ (height in meters)². Height in meters = height in cm ÷ 100.
Example
Someone who weighs 70 kg and is 170 cm tall has height 1.7 m. BMI = 70 ÷ (1.7 × 1.7) ≈ 24.2, which falls in the normal range on the common WHO adult scale.
Frequently asked questions
Is BMI accurate for athletes?
Muscular people can show a high BMI without high body fat. BMI is only a quick screen, not a diagnosis.
What ranges does CalcKit use?
Underweight below 18.5, normal 18.5–24.9, overweight 25–29.9, obese 30 and above (adult WHO-style bands).
Should I change my diet based only on BMI?
No. Discuss weight and health goals with a qualified clinician, especially if you have medical conditions.