BMI Tool
Estimate adult body mass index from height and weight, view standard BMI categories, and compare current weight with healthy-range boundaries. Explore a chosen target BMI, target weight difference, BMI prime, category table and interactive visual results.
Your measurements
Adults aged 20+Your BMI is within the standard adult healthy range.
BMI scale
Your BMI: 23.5BMI and weight comparison
Standard adult WHO cut-offsStandard adult BMI classification
| Category | BMI | Weight at your height (kg) |
|---|
BMI is a screening indicator, not a diagnosis. It does not distinguish muscle from fat and may be less informative in pregnancy, for athletes, and for some ethnic groups. Adult categories are not suitable for children or teenagers. Speak to a qualified healthcare professional for individual guidance.
Table of Contents
Highlights
- Instant adult BMI score and weight classification
- Metric and imperial measurement inputs
- Adjustable target BMI with weight difference
- Visual BMI scale and weight comparison chart
- Healthy-weight range, BMI prime and CSV, JSON or PNG exports
How BMI Tool Works?
Body mass index (BMI) relates body weight to the square of height. It uses the same formula for adults regardless of sex or age; these inputs do not alter the calculated BMI.
For example, at 72 kg and 1.75 m tall, BMI is approximately 23.5. Standard adult thresholds determine the category.
| Adult category | BMI |
|---|---|
| Underweight | Below 18.5 |
| Healthy weight | 18.5 to below 25 |
| Overweight | 25 to below 30 |
| Obesity | 30 or above |
The displayed healthy-weight interval uses BMI values 18.5 and 24.9 multiplied by height squared. A selected target BMI determines a corresponding target weight, and subtracting current weight gives the weight difference.
BMI prime is BMI divided by 25. The scale indicates the current category, while the comparison chart and table show category boundary weights, current weight and target weight for the entered height.
Practical Use Cases
Adults monitoring weight: Compare BMI with standard categories and review the weight interval associated with the entered height.
People setting a weight goal: Adjust the target BMI slider to see the corresponding target weight and difference from current weight.
Fitness enthusiasts: Use BMI prime and the comparison chart as general reference points, remembering that muscularity can affect interpretation.
Health educators: Demonstrate how the same height leads to different weight thresholds across the four adult BMI categories.
People preparing for a consultation: Export the calculated values as CSV or JSON, or save the comparison chart as a PNG to discuss with a healthcare professional.
Accuracy and Limitations
The calculation follows BMI = weight divided by height squared, so numerical accuracy depends on the measurements supplied; values and chart labels are rounded for display. Standard adult category cut-offs do not measure body fat or distinguish muscle from fat. Age (20–120) and optional sex do not change the formula. Results are not designed for children, teenagers or pregnancy, and interpretation can vary with ethnicity and individual health circumstances. The displayed upper healthy-weight value uses BMI 24.9, while the category ends just below 25; target BMI choices are limited to 18.5–30.
