BMI Calculator
Calculate your Body Mass Index instantly. See your category, healthy weight range, and what it means for your health.
BMI Classification (WHO)
| Category | BMI Range | Health Risk |
|---|---|---|
| Underweight | < 18.5 | Malnutrition risk |
| Normal weight | 18.5 – 24.9 | Low risk |
| Overweight | 25 – 29.9 | Moderate risk |
| Obese | ≥ 30 | High risk |
How to Use the BMI Calculator
ToolsPix BMI Calculator computes your Body Mass Index directly in your browser. No data is ever sent to a server — every calculation runs locally using JavaScript.
Steps to calculate your BMI
Select your preferred unit system using the Metric or Imperial toggle. Enter your height and weight, then click Calculate BMI. Your BMI value, category, and healthy weight range appear instantly below the form.
What the result shows
- Your BMI number and category (Underweight, Normal, Overweight, or Obese).
- A visual scale bar with a needle showing your position across all four ranges.
- Your healthy weight range and how much weight to lose or gain to reach it.
- Your entered height and weight displayed for easy reference.
About BMI
Body Mass Index is a simple number derived from height and weight. The formula is: BMI = weight (kg) ÷ height² (m²). The WHO uses it as a population-level screening tool to identify potential weight-related health risks.
BMI does not distinguish between muscle mass, bone density, or fat distribution. Athletes and people with high muscle mass may score in the overweight range while having low body fat. Use it as a starting point, not a diagnosis.
FAQ
Is my BMI data sent to a server?
No. All calculations happen locally in your browser using JavaScript. No data is transmitted to any server, and nothing is stored or logged.
What is a healthy BMI range?
According to the World Health Organization (WHO), a BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is classified as obese.
Is BMI accurate for athletes and muscular people?
BMI doesn't distinguish between muscle and fat. Athletes and people with high muscle mass may have a BMI in the overweight range despite having low body fat. BMI is a population-level screening tool, not a precise individual health measure.
How do I calculate BMI in imperial units?
Switch to the Imperial tab, enter your height in feet and inches and your weight in pounds, then click Calculate BMI. The formula used is: BMI = (weight in lb ÷ height in inches²) × 703.
Does BMI apply to children?
Standard WHO BMI ranges are designed for adults aged 18 and over. For children and teenagers, BMI-for-age percentile charts are used instead. This tool is intended for adult use.