BMI Calculator
Use your height and weight to calculate Body Mass Index (BMI), see your category, and check a healthy weight range for your height.
Result
Enter your details and calculate to see BMI, category, and a healthy weight range for your height.
BMI Categories (WHO)
BMI is a screening metric used to classify weight status in adults.
| Category | BMI Range |
|---|---|
| Underweight | Below 18.5 |
| Normal weight | 18.5 - 24.9 |
| Overweight | 25.0 - 29.9 |
| Obesity | 30.0 and above |
BMI Formula
Metric: BMI = weight (kg) / [height (m)]^2
U.S. units: BMI = 703 x weight (lb) / [height (in)]^2
Healthy Weight Range
The healthy-weight estimate uses the BMI normal range (18.5 to 24.9) and your height. It gives a practical range, not an exact target.
How to Use BMI in Practice
- Use BMI as an initial screen, then add waist and body-fat context.
- Track BMI trend over time instead of reacting to one reading.
- Pair BMI with your training performance and recovery markers.
- For planning calories, combine BMI with your TDEE estimate.
BMI vs Body Fat
BMI does not separate fat mass from lean mass. Two people can have the same BMI but very different body composition.
If you lift regularly or carry more muscle, BMI can classify you as overweight even when body fat is healthy. Use body-fat estimates and waist trend for better context.
Common Mistakes
- Mixing units accidentally (for example entering lbs in metric mode).
- Using outdated height or body weight values.
- Ignoring trend direction and relying on one calculation only.
- Using BMI alone to make aggressive diet decisions.
Quick FAQ
Is BMI accurate for everyone? It is a useful screen, but not a full body-composition metric.
Should I use BMI for calorie targets? Use BMI with your TDEE result, activity level, and trend data.
How often should I recalculate? Every 2-4 weeks is enough for most people.
BMI is a screening estimate and not a diagnosis. For clinical decision-making, consult a qualified healthcare professional.