BMI Calculator
Calculate your Body Mass Index (BMI) accurately and locally. Your data never leaves your browser.
Your Measurements
boltResults update instantly as you type.
Enter data
Adjust your inputs to see the magic happen.
Ideal Range
Complete the form to see your healthy weight range.
BMI Categories
Underweight
Below 18.5
Normal Weight
18.5 – 24.9
Overweight
25.0 – 29.9
Obese
30.0 or higher
Frequently Asked Questions
How is BMI calculated?
BMI = weight (kg) divided by height squared (m²). A BMI between 18.5 and 24.9 is generally considered a healthy range for adults, though it's a screening measure, not a diagnosis.
Are there limits to what BMI can tell me?
Yes. BMI doesn't distinguish muscle from fat and doesn't account for age, sex, or body composition — athletes often have a high BMI with low body fat. Consult a healthcare professional for a full assessment.
Is my health data private?
Yes. Your height and weight are processed entirely in your browser and never sent to or stored on any server.