Calculator
BMI Calculator
Body mass index is a quick screening number based on your height and weight. See where you fall and what the range means, with the context BMI alone leaves out.
Your details
Your result
Normal weight
- Under 18.5, underweight
- 18.5–24.9, normal
- 25–29.9, overweight
- 30+, obese
BMI is a screening tool, not a diagnosis. It doesn't account for muscle, body composition, age or sex.
What is BMI?
Body mass index (BMI) is a simple ratio of your weight to your height. It's calculated as weight in kilograms divided by height in metres squared. Because it needs only two easy measurements, it's widely used as a quick population-level screening tool for weight categories.
What BMI doesn't tell you
BMI treats all weight the same, so it can't tell muscle from fat. A very muscular person can have a "high" BMI while carrying little fat, and BMI can also miss low muscle mass in older adults. It also doesn't consider where fat is stored, which matters for health. Treat it as one rough signal among several, not the whole picture.
Better-together tools
For a fuller view, pair BMI with body composition and energy needs.
Frequently asked questions
What is BMI?
Body mass index is a ratio of your weight to your height, calculated as weight in kilograms divided by height in metres squared. It is widely used as a quick screening tool for weight categories.
What is a healthy BMI?
A BMI between 18.5 and 24.9 is generally considered the healthy range. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above is in the obese range.
Is BMI accurate?
BMI is a useful screening tool but it cannot tell muscle from fat. Very muscular people may have a high BMI with little fat, and it can miss low muscle mass in older adults. Treat it as one signal among several.
Should I rely on BMI alone?
No. Pair it with measures like body fat and waist circumference, and remember welanutria provides estimates for general information only, not medical advice.
welanutria provides estimates for general information only and is not medical advice. Consult a qualified professional about your weight and health.