BMI Calculator
Check your body mass index in seconds. Use metric units or switch to feet, inches, and pounds.
BMI is a screening number, not a diagnosis. Talk to a health professional about what it means for you.
What is BMI?
Body Mass Index is a simple number calculated from your height and weight. Health organizations use it as a quick screening tool, and it sorts adults into four widely used ranges: underweight (below 18.5), healthy (18.5 to 24.9), overweight (25 to 29.9), and obesity (30 and above). It takes seconds to compute, which is why it shows up on so many health forms.
What BMI does not tell you
BMI cannot see the difference between muscle and fat, so very muscular people can land in the overweight range while being perfectly fit. It also does not account for age, bone structure, or where weight sits on the body. Think of it as a first check, not a final answer. If your result surprises you, or if you have health concerns, a professional can give you the full picture.
Frequently asked questions
What is BMI?
Body Mass Index is a number calculated from your height and weight. It sorts adults into four common ranges: underweight (below 18.5), healthy (18.5 to 24.9), overweight (25 to 29.9), and obesity (30 and above).
Is BMI accurate?
BMI is a quick screening tool, not a full health check. It does not account for muscle mass, bone density, or body composition, so athletes and older adults can get misleading results. Treat it as a starting point.
How is BMI calculated?
BMI is your weight in kilograms divided by the square of your height in meters. This calculator also accepts feet, inches, and pounds and converts them for you.
What is a healthy BMI?
A BMI between 18.5 and 24.9 is considered the healthy range for most adults. If your result falls outside it, consider talking to a health professional rather than worrying on your own.
Is my height and weight stored?
No. The calculation happens in your browser and your numbers are never uploaded, saved, or shared.