BMI Calculator
Calculate your Body Mass Index instantly. Supports metric (kg/cm) and imperial (lbs/ft) with health category.
BMI Categories
Understanding Your BMI
Body Mass Index (BMI) is a numerical value calculated from your height and weight. It is a widely used screening tool that gives a rough indication of whether you are at a healthy weight for your height. BMI was developed by Belgian mathematician Adolphe Quetelet in the 1830s and has been used in health research for decades.
A BMI between 18.5 and 24.9 is considered healthy for most adults. Below 18.5 indicates underweight, which can be associated with nutritional deficiencies. A BMI of 25-29.9 indicates overweight, while 30 or above is classified as obese, which increases the risk of conditions like diabetes, heart disease and joint problems.
⚠️ Important: BMI is a screening tool, not a diagnostic tool. It does not measure body fat directly. Consult a healthcare professional for a complete health assessment.
Frequently Asked Questions
How is BMI calculated?▼
BMI = Weight (kg) ÷ Height² (m). For example, if you weigh 70 kg and are 170 cm (1.70 m) tall: BMI = 70 ÷ (1.70 × 1.70) = 70 ÷ 2.89 = 24.2 (Normal weight).
Is BMI accurate for everyone?▼
BMI has limitations. It may overestimate body fat in muscular people (like athletes) and underestimate it in older adults who have lost muscle. It also does not account for fat distribution, age, or gender differences.
What is the ideal BMI?▼
For most adults, a BMI between 18.5 and 24.9 is considered healthy. However, the optimal range may vary slightly by age, gender and ethnicity.
Is this calculator free?▼
Yes, 100% free. No account or sign-up needed.