TOOLGENIEBMI Calculator
Calculate your Body Mass Index in metric or imperial units
How to Use the BMI Calculator
- Choose your unit system — Metric (centimeters and kilograms) or Imperial (inches and pounds).
- Enter your height in the first field. Use cm for metric or inches for imperial.
- Enter your weight in the second field. Use kg for metric or lbs for imperial.
- Click "Calculate BMI" to see your Body Mass Index and category instantly.
- Review the visual scale to see where your BMI falls on the underweight, normal, overweight, or obese range.
About the BMI Calculator
The BMI Calculator by ToolGenie is a free, browser-based tool that calculates your Body Mass Index instantly. BMI is a widely used screening measure to determine whether you are underweight, normal weight, overweight, or obese based on your height and weight.
This tool runs entirely in your browser. No data is sent to any server or stored anywhere. Your measurements stay completely private on your device. We support both metric (cm/kg) and imperial (inches/lbs) units so you can use whichever system you prefer.
The calculator uses the standard WHO classification: underweight (BMI < 18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30). The visual indicator helps you quickly see where your result falls on the scale. Remember that BMI is a screening tool and does not diagnose body fatness or health. Consult a healthcare provider for personalized advice.
Frequently Asked Questions (FAQ)
What is BMI and how is it calculated?
BMI (Body Mass Index) is a measure of body fat based on height and weight. The formula is BMI = weight (kg) ÷ height (m)². For imperial units, weight in pounds and height in inches are converted to metric equivalents before calculation. Our calculator handles both metric and imperial units automatically.
What do the BMI categories mean?
The standard WHO categories are: Underweight (BMI below 18.5), Normal weight (18.5–24.9), Overweight (25–29.9), and Obese (30 and above). These ranges help identify potential weight-related health risks. BMI is a screening tool and does not directly measure body fat percentage.
Is BMI accurate for everyone?
BMI is a useful population-level screening tool but has limitations. It does not distinguish between muscle and fat, so athletes with high muscle mass may have a high BMI despite being healthy. It also may not accurately reflect body composition in older adults, children, or pregnant women. For personalized health advice, consult a healthcare provider.
Can I use this BMI calculator in metric and imperial units?
Yes. Our calculator supports both metric (centimeters and kilograms) and imperial (inches and pounds) units. Simply toggle between Metric and Imperial at the top of the form. Enter your height and weight in either system, and the result will be calculated instantly. The BMI value is the same regardless of which units you use.
Is my data private when I use this BMI calculator?
Absolutely. All calculations are performed entirely in your browser. No height, weight, or BMI data is sent to any server, stored in a database, or logged. Your measurements remain completely private on your device.
What is a healthy BMI range?
A BMI between 18.5 and 24.9 is generally considered healthy for most adults. BMI below 18.5 may indicate underweight, while 25–29.9 suggests overweight and 30+ indicates obesity. These ranges are guidelines; individual factors like age, sex, muscle mass, and ethnicity can affect interpretation. Discuss your results with a healthcare professional for personalized guidance.
Tips for Using the BMI Calculator
- Measure accurately: Use a reliable scale for weight and measure height without shoes for the most accurate results.
- Choose your preferred units: Use metric if you are more familiar with cm and kg, or imperial for inches and pounds.
- Understand the limitations: BMI does not account for muscle mass, bone density, or body composition. Athletes or very muscular individuals may have higher BMIs despite being fit.
- Use it as a screening tool: BMI helps identify potential weight-related health risks but should not replace professional medical advice. Consult a doctor for personalized health guidance.
- Track changes over time: Use the calculator periodically to monitor weight trends, but focus on overall health—diet, exercise, and lifestyle—rather than just the number.