How is BMI calculated?

BMI is calculated by dividing your weight in kilograms by the square of your height in meters. The formula is: BMI = weight (kg) ÷ height² (m). For example, someone weighing 70 kg at 1.75 m has a BMI of 70 ÷ (1.75 × 1.75) = 22.9.

Is BMI accurate for everyone?

BMI has limitations. It doesn't distinguish between muscle and fat, so athletes may have a high BMI despite low body fat. It also doesn't account for age, sex, ethnicity, or where fat is distributed. Use it as a general guideline, not a definitive health measure.

Can I use pounds and inches instead of kg and cm?

Our calculator uses metric units (kg and cm). To convert: divide your weight in pounds by 2.205 to get kilograms, and multiply your height in inches by 2.54 to get centimeters.

What should I do if my BMI is outside the healthy range?

If your BMI indicates you're underweight or overweight, it's a good idea to speak with a healthcare provider. They can help determine whether your weight poses health risks and recommend appropriate diet and exercise changes.

BMI Calculator — Free & Instant

The BMI Calculator helps you determine your Body Mass Index — a widely used screening tool that estimates body fat based on your weight and height. BMI is used by healthcare professionals around the world to categorize individuals as underweight, normal weight, overweight, or obese. While BMI is not a direct measure of body fat and doesn't account for muscle mass or body composition, it's a fast, free, and useful starting point for assessing your health. Enter your height and weight below to get your result in seconds.

Weight(kg)

Height(cm)

Frequently Asked Questions

A healthy BMI is generally considered to be between 18.5 and 24.9. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese. These ranges apply to most adults, but may differ for children, the elderly, and athletes.

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