BMI Calculator
Enter your weight and height to estimate your Body Mass Index (BMI).
What is BMI and why does it matter?
BMI (Body Mass Index) is a quick screening tool that compares your weight to your height. It helps estimate whether your body weight is in a range generally associated with lower or higher health risk. It is widely used in clinics, public health reports, and personal wellness tracking because it is simple and fast.
The key point: BMI is not a diagnosis. It is a useful starting number, not a complete health profile. Think of it as one data point alongside blood pressure, activity level, diet quality, sleep, stress, and medical history.
How this BMI calculator works
Metric formula
BMI = weight (kg) / [height (m)]²
Imperial formula
BMI = 703 × weight (lb) / [height (in)]²
This page supports both metric and imperial units. Once you enter your numbers, the calculator returns:
- Your BMI value rounded to one decimal place
- Your category (Underweight, Normal weight, Overweight, or Obesity)
- A general healthy-weight range based on your height
BMI categories for adults
- Underweight: BMI below 18.5
- Normal weight: BMI 18.5 to 24.9
- Overweight: BMI 25.0 to 29.9
- Obesity: BMI 30.0 and above
These ranges are standard adult cutoffs used in many countries. For children and teens, BMI interpretation is different and based on age- and sex-specific percentiles.
Important limitations of BMI
BMI does not directly measure body fat, muscle mass, bone density, or fat distribution. Because of that, two people can have the same BMI but very different health profiles.
- A muscular athlete may have a higher BMI without excess body fat.
- An older adult may have a “normal” BMI but lower muscle mass and higher body fat percentage.
- BMI does not show where fat is stored; abdominal fat can increase risk even at moderate BMI values.
Using BMI in a practical way
Use your BMI trend over time rather than obsessing over a single reading. Pair it with waist circumference, daily movement, strength, cardio fitness, and routine health checkups. Small, consistent habits usually beat extreme short-term changes.
Healthy next steps
- Prioritize balanced meals with enough protein, fiber, and hydration.
- Build a routine of resistance training plus regular walking or cardio.
- Sleep 7–9 hours most nights for recovery and appetite regulation.
- Review your numbers with a qualified healthcare professional if needed.
If your calculated BMI is outside your target range, treat that as useful feedback—not a label. Sustainable lifestyle improvements can meaningfully improve long-term health, energy, and quality of life.