UlvixorBMI Calculator
Calculate your Body Mass Index (BMI) from your weight and height, and see which general category the result falls into according to standard WHO ranges. It's a quick reference, not a medical diagnosis.
How it works
- Enter your weight in kilograms.
- Enter your height in centimeters.
- The tool converts height to meters and applies the standard formula: weight (kg) / height (m)².
- The result is rounded to one decimal place and classified into one of four categories: underweight, normal weight, overweight, or obesity, based on the WHO's general thresholds for adults.
- BMI and category update automatically as you change the values.
Use cases
- Getting a quick reference for your BMI without looking up the formula or doing the calculation by hand.
- Tracking how your BMI changes over time alongside changes in weight.
- Understanding what general range your current weight falls into relative to your height before a medical appointment.
- Calculating another person's BMI (a family member, a patient) by entering their weight and height.
Use cases
- Getting a quick reference for your BMI without looking up the formula or doing the calculation by hand.
- Tracking how your BMI changes over time alongside changes in weight.
- Understanding what general range your current weight falls into relative to your height before a medical appointment.
- Calculating another person's BMI (a family member, a patient) by entering their weight and height.
Common mistakes
- Interpreting BMI as a precise medical diagnosis of health or body composition.BMI is only a general reference based on weight and height; it doesn't distinguish between muscle mass and fat mass, and it doesn't account for age, sex, or individual body composition. A very muscular person can have a high BMI without excess fat. Consult a healthcare professional for a complete evaluation.
- Entering height in meters (for example, 1.70) in the field that expects centimeters.The height field expects centimeters (for example, 170), not meters. Entering 1.70 would give a nonsensical result, since the formula would square a number much smaller than expected.
- Comparing a child's or teenager's BMI against the same categories used for adults.This calculator's thresholds correspond to the general ranges for adults. BMI in children and teenagers is evaluated using percentile tables specific to age and sex, not these fixed categories.
Frequently asked questions
BMI = weight (kg) / height (m)². For example, a person weighing 70 kg and standing 1.70 m tall has a BMI of 70 / (1.70 × 1.70) ≈ 24.2.
Underweight (BMI below 18.5), normal weight (18.5 to 24.9), overweight (25 to 29.9), and obesity (30 or above), following the general ranges used by the World Health Organization for adults.
No. It's a general formula that only uses weight and height, without adjusting for body composition, age, sex, or other individual factors. That's why it may not accurately reflect the health of very muscular people, athletes, or older adults.
No. The calculation is performed entirely in your browser using JavaScript. No data is sent to or stored on any server.
Alternatives
The BMI formula (weight / height²) can be calculated with any basic calculator, and many health or fitness apps include it alongside other metrics like body fat percentage. This tool is useful for a quick check without opening an app or looking up the formula, showing both the number and the category right away.