BMI Calculator
Calculate your Body Mass Index and find your healthy weight range.
How to Use BMI Calculator
- 1Select your preferred unit system: Metric (kg/cm) or Imperial (lbs/ft/in).
- 2Enter your weight in the weight field.
- 3Enter your height in the height field.
- 4Your BMI, weight category, and healthy weight range are calculated instantly.
- 5Reference the category chart at the bottom to understand what your BMI means.
Frequently Asked Questions
What is BMI?
BMI (Body Mass Index) is a numerical value calculated from a person's weight and height. It's used as a screening tool to indicate whether a person may be underweight, normal weight, overweight, or obese.
How is BMI calculated?
BMI = weight (kg) ÷ height² (m²). For imperial units, BMI = 703 × weight (lbs) ÷ height² (inches²). The same categories apply regardless of which unit system is used.
Is BMI an accurate measure of health?
BMI is a useful population-level screening tool, but it has limitations. It doesn't distinguish between muscle and fat mass — athletes may have high BMIs due to muscle. It also doesn't account for age, sex, ethnicity, or body fat distribution. Always consult a healthcare provider for a comprehensive health assessment.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is classified as 'Normal weight' for most adults. Below 18.5 is underweight. 25–29.9 is overweight. 30 and above is classified as obese (with further classes above 35 and 40).
About BMI Calculator
The BMI Calculator is a quick, free tool for estimating your body mass index — a widely used indicator of whether your weight falls within a healthy range for your height. While not a diagnostic tool, BMI calculations are routinely used in clinical settings as a first-pass screening for weight-related health risks.
The calculator supports both metric (kilograms and centimeters) and imperial (pounds, feet, and inches) input, making it accessible to users worldwide. It instantly computes your BMI, identifies your weight category, and shows the healthy weight range specific to your height — giving you a concrete target if you're looking to reach or maintain a healthy weight.
The six BMI categories follow the World Health Organization classifications: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), Obese Class I (30–34.9), Obese Class II (35–39.9), and Obese Class III (40 and above). The color-coded scale provides an at-a-glance view of where your BMI falls relative to all categories.
It's important to note that BMI is a screening tool, not a diagnostic measure. Factors like age, muscle mass, bone density, and ethnicity can affect the interpretation of BMI. For example, athletes and bodybuilders often have high BMIs due to muscle mass rather than excess fat. Children and the elderly also use different BMI reference charts. Always discuss your results with a qualified healthcare provider.