Calculate your Body Mass Index (BMI) instantly with our free online BMI Calculator. BMI is a simple weight-to-height ratio that helps you understand whether you are underweight, at a healthy weight, overweight, or obese. By knowing your BMI, you can make better health and fitness decisions. Just enter your weight and height below to get accurate, instant results — no math required!
BMI Calculator
BMI Categories & Health Risks
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Possible nutrient deficiency |
| 18.5 – 24.9 | Healthy Weight | Low risk |
| 25 – 29.9 | Overweight | Increased risk |
| 30 and above | Obese | High risk |
What is BMI and why is it important?
Body Mass Index (BMI) is a measure that compares your weight to your height to estimate body fat. It helps identify if you are underweight, healthy weight, overweight, or obese, which can affect your overall health.
How do I calculate my BMI manually?
You can calculate BMI by dividing your weight in kilograms by your height in meters squared. Formula: BMI = weight (kg) ÷ [height (m)]².
What is a healthy BMI range for adults?
For most adults, a BMI between 18.5 and 24.9 is considered healthy. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese.
Can BMI be inaccurate for muscular people?
Yes. BMI doesn’t distinguish between muscle and fat. Muscular individuals may have a higher BMI but low body fat.
How often should I check my BMI?
Checking your BMI every 3–6 months is enough for most people. Frequent checks are not necessary unless you’re on a weight management program.
Is BMI different for men and women?
The calculation is the same for both, but body fat distribution and healthy ranges may vary slightly between men and women.
Does age affect BMI interpretation?
Yes. For older adults, a slightly higher BMI may be healthy. BMI charts for children and teens are age- and sex-specific.
