What is a normal BMI range?

According to WHO: Underweight: BMI < 18.5, Normal weight: 18.5–24.9, Overweight: 25.0–29.9, Obese Class I: 30.0–34.9, Obese Class II: 35.0–39.9, Obese Class III (Morbidly Obese): ≥ 40.

What is the BMI formula?

BMI = Weight (kg) / Height (m)². For imperial units: BMI = (Weight in pounds / Height in inches²) × 703.

Is BMI accurate for athletes and bodybuilders?

No. BMI does not distinguish between muscle and fat. Athletes and bodybuilders often have high BMI scores despite having low body fat percentages. For them, body fat percentage measurement is more accurate.

Is BMI different for Asians?

Yes. The WHO has recommended lower BMI cutoffs for Asian populations. For Asians: Underweight <18.5, Normal 18.5–22.9, Overweight 23.0–24.9, Obese ≥25. Our calculator uses standard WHO thresholds with an option to apply Asian standards.

Can children use this BMI calculator?

This calculator is designed for adults (18+). For children and teens, BMI is interpreted differently using age and sex-specific percentiles. Consult a pediatrician for children's weight assessment.

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BMI Calculator

Calculate your Body Mass Index and find out if you are underweight, normal or obese.

Height (cm)

Weight (kg)

BMI Range	Category
0 – 18.5	Underweight
18.5 – 25	Normal weight
25 – 30	Overweight
30 – 35	Obese (Class I)
35 – 40	Obese (Class II)

How to Use BMI Calculator

1
Select your unit system: Metric (kg/cm) or Imperial (lbs/ft/in).
2
Enter your height in the appropriate unit.
3
Enter your current weight.
4
Your BMI and weight category are calculated instantly.
5
View the healthy weight range for your height and your position on the BMI scale.

About BMI Calculator

BMI (Body Mass Index) is a widely used screening tool that estimates body fat based on your height and weight. Our BMI Calculator gives you an instant BMI score along with your weight category (Underweight, Normal weight, Overweight, or Obese) and a visual indicator on the BMI scale.

The tool supports both metric (kg/cm) and imperial (lbs/ft/in) units, making it accessible for users worldwide. Along with your BMI, you'll see the healthy weight range for your height — showing exactly how many kilograms you'd need to gain or lose to reach the normal BMI range.

BMI is used by healthcare professionals as a quick initial assessment of weight-related health risk. While BMI doesn't directly measure body fat and doesn't account for muscle mass, it's a valuable starting point for understanding your weight status. The World Health Organization (WHO) defines normal BMI as 18.5 to 24.9.