BMI Calculator
Example Data Table
| Example | Height | Weight | BMI | Category |
|---|---|---|---|---|
| Adult A | 170 cm | 60 kg | 20.76 | Normal weight |
| Adult B | 175 cm | 82 kg | 26.78 | Overweight |
| Adult C | 180 cm | 98 kg | 30.25 | Obesity class I |
Formula Used
The main formula is:
BMI = weight in kilograms / height in meters²
For US units, the calculator first converts pounds to kilograms. It also converts inches to meters. Then it applies the same metric formula.
Healthy weight range uses:
Low healthy weight = 18.5 × height²
High healthy weight = 24.9 × height²
BMI Prime is calculated as BMI / 25. Ponderal Index is calculated as weight / height³.
How to Use This Calculator
- Select the measurement system that matches your data.
- Enter your height and weight in the visible fields.
- Add age, gender note, target BMI, and waist size if needed.
- Press the calculate button to view the result above the form.
- Use the CSV or PDF buttons to save your report.
BMI Calculator Guide
What BMI Measures
BMI means body mass index. It compares body weight with height. The value is useful for quick adult screening. It is not a full medical diagnosis. It does not measure body fat directly. Still, it gives a practical first view of weight status. Many clinics use it because it is fast and simple.
Why This Calculator Helps
This calculator supports several unit systems. You can enter centimeters, meters, feet, inches, pounds, stones, or kilograms. The tool converts values before applying the standard formula. That reduces manual conversion errors. It also shows healthy weight range, target weight, BMI Prime, and Ponderal Index.
Understanding the Result
A BMI below 18.5 is usually called underweight. A BMI from 18.5 to 24.9 is commonly called normal weight. A BMI from 25 to 29.9 is overweight. A BMI of 30 or higher enters obesity ranges. These categories apply mainly to adults. Children, athletes, pregnant users, and older adults may need different review methods.
Planning Weight Goals
The healthy range is calculated from your height. It shows the weight span linked with BMI values from 18.5 to 24.9. You can also enter a target BMI. The calculator then estimates a target weight. This makes planning easier. Use small changes. Track progress over time. Avoid unsafe crash diets.
Using Advanced Metrics
BMI Prime compares your BMI with 25. A value near one sits near the upper normal boundary. Ponderal Index can be helpful for very tall or short people. Waist-to-height ratio adds another screening view. Enter waist size when you want that extra note. For health decisions, ask a qualified professional.
Frequently Asked Questions
1. What is BMI?
BMI is body mass index. It compares weight with height. It is often used as a quick adult weight screening number.
2. Is BMI a medical diagnosis?
No. BMI is a screening tool only. It cannot measure body fat, muscle mass, or complete health status by itself.
3. Which BMI range is considered normal?
For many adults, 18.5 to 24.9 is considered the normal BMI range. Individual health review may still differ.
4. Can athletes get misleading BMI results?
Yes. Athletes may have higher muscle mass. That can raise BMI without meaning excess body fat is present.
5. Does this calculator support pounds?
Yes. Select the US option. Then enter height in feet and inches, and enter weight in pounds.
6. What is BMI Prime?
BMI Prime divides your BMI by 25. It shows how your value compares with the upper normal adult BMI limit.
7. What is a healthy weight range?
It is the estimated weight range linked with BMI values from 18.5 to 24.9 for your entered height.
8. Can I download my BMI result?
Yes. After entering values, press the CSV or PDF button. The page creates a simple downloadable report.