BMI Calculator
Calculate your Body Mass Index (BMI) using metric or imperial units and see which standard weight category your result falls into.
What is a BMI calculator?
A BMI calculator estimates your Body Mass Index, a simple ratio of weight to height that places you in a broad weight category. It is the most widely used screening figure in healthcare because it needs only two measurements and gives a quick sense of whether your weight sits in a healthy range for your height. Enter your details in metric or imperial units and the tool returns your BMI and category at once.
Understanding your BMI category
The standard adult ranges are: below 18.5 is underweight, 18.5 to 24.9 is a healthy weight, 25 to 29.9 is overweight, and 30 or above is in the obese range. These cut-offs are guidelines, not diagnoses. BMI does not distinguish muscle from fat, so very athletic people can read as overweight despite low body fat. Treat your number as a starting point for a conversation, not a verdict.
Why BMI has limits
BMI is popular because it is easy, but it is a blunt instrument. It ignores muscle mass, bone density, age, sex and where fat is stored on the body. A waist measurement or body-fat percentage can add useful context. For children, pregnant people and serious athletes, BMI is especially unreliable. Always discuss meaningful health decisions with a qualified professional rather than acting on a single number.
Frequently Asked Questions
What is a healthy BMI range?
For most adults a BMI between 18.5 and 24.9 is considered a healthy weight, though individual circumstances vary.
Is BMI accurate for athletes?
Not always. Muscle weighs more than fat, so muscular people may show a high BMI despite being very healthy.
Does BMI work the same for men and women?
The standard adult categories are the same for both, but body composition differs, so BMI should be read alongside other indicators.
Should I make health decisions based on BMI alone?
No. BMI is a quick screening figure. For real guidance, consult a doctor or qualified health professional who can consider your full situation.