Free BMI Calculator
Check your Body Mass Index. Supports metric (cm/kg) and imperial (ft/in, lbs).
The BMI Calculator estimates your Body Mass Index from your height and weight, accepting both metric and imperial inputs. It gives you a quick, private check that runs entirely on your device.
What is a BMI Calculator?
A BMI (Body Mass Index) calculator is a health tool that helps determine whether your weight is within a healthy range for your height. It provides a numerical value calculated from your weight and height, categorizing you as underweight, normal weight, overweight, or obese. While not perfect, BMI offers a quick, standardized way to assess weight-related health risks.
BMI is widely used by healthcare professionals as a screening tool to identify potential weight issues. It correlates reasonably well with body fat for most people and helps identify those who may benefit from further health assessments. However, it's important to understand that BMI doesn't measure body fat directly and can be misleading for individuals with high muscle mass, athletes, or those with unusual body proportions.
Our BMI calculator supports both metric and imperial units, making it accessible worldwide. It provides instant results and categorizes your BMI according to standard health guidelines. The tool runs entirely in your browser with no data collection, ensuring complete privacy. For a more accurate health assessment, consider using this tool alongside other metrics like waist circumference, body fat percentage, and professional medical advice.
How to use this BMI Calculator
- Select your preferred unit system (Metric or Imperial) using the dropdown.
- Enter your height in the appropriate fields (cm for metric, feet/inches for imperial).
- Enter your weight in kilograms (metric) or pounds (imperial).
- View your BMI value and health category instantly.
- Adjust your inputs to see how changes affect your BMI category.
FAQ
What is a normal BMI?
A BMI of 18.5–24.9 is considered normal. Below 18.5 is underweight, 25–29.9 is overweight, and 30+ is obese.
Is BMI accurate for everyone?
BMI is a general screening tool. It doesn't account for muscle mass, so very muscular people may have a high BMI despite being healthy.
How is BMI calculated?
BMI = weight (kg) / height² (m²). For imperial: BMI = 703 × weight (lbs) / height (in)².
Is my height and weight data private?
No. Your height, weight and the BMI result are all computed in your browser and never uploaded or stored.