BMI Calculator

BMI Formula & Categories

Body Mass Index (BMI) = weight (kg) ÷ height (m)². This calculator accepts kilograms and centimetres, or pounds with feet and inches.

BMI Categories for Adults (WHO / Health Canada)

BMI does not distinguish muscle from fat and is not suitable for athletes or pregnant women. Results are for reference only — speak to your doctor about any health concerns.

Frequently Asked Questions

What is a healthy BMI?

Using the standard WHO ranges used in Canada, a BMI of 18.5–24.9 is a healthy weight, below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese.

How is BMI calculated?

BMI = weight (kg) ÷ height (m)². For example, 72 kg at 1.75 m gives a BMI of about 23.5. The calculator converts pounds, feet and inches for you when you use imperial units.

Is BMI accurate?

BMI does not distinguish muscle from fat, so it can be misleading for athletes, pregnant women and older adults. Use it as a general screening tool and consider your waist measurement and body-fat percentage as well.

What is my healthy weight range?

A healthy weight is a BMI of 18.5–24.9 multiplied by your height (m)². At 1.75 m that is roughly 57–76 kg, or about 125–168 lb.

Does Canada use a different BMI range?

Health Canada uses the same WHO adult categories. The cut-offs are guidance, not strict limits, and health risk also depends on waist circumference, ethnicity and overall fitness.