BMI Calculator
Calculate your Body Mass Index instantly. Supports Imperial and Metric.
How to Use the BMI Calculator
Choose Imperial or Metric, enter your weight and height, then click Calculate BMI. Here are two quick examples:
Example 1 — Metric
Weight: 72 kg · Height: 175 cm. Result: BMI 23.5 — Normal weight.
Example 2 — Imperial
Weight: 195 lbs · Height: 5 ft 10 in. Result: BMI 28.0 — Overweight.
BMI Formula Explained
Metric: BMI = weight (kg) ÷ height (m)²
Imperial: BMI = 703 × weight (lbs) ÷ height (in)²
BMI compares your weight to your height to give a general indicator of body fatness. For example, someone who weighs 70 kg and is 1.75 m tall has a BMI of 70 ÷ (1.75 × 1.75) = 22.9, which falls in the Normal range.
BMI Categories
Underweight (BMI < 18.5)
May indicate insufficient nutrition or an underlying health issue. A doctor can help identify the cause and recommend next steps.
Normal weight (BMI 18.5 – 24.9)
Associated with the lowest health risks for most adults. Maintaining a balanced diet and regular activity helps stay in this range.
Overweight (BMI 25 – 29.9)
May increase the risk of conditions like high blood pressure or type 2 diabetes. Modest lifestyle changes can make a meaningful difference.
Obese (BMI ≥ 30)
Linked to higher risk of serious health conditions. Speaking with a healthcare provider is a good first step toward a personalized plan.
FAQs
Is BMI an accurate measure of health?
BMI is a useful screening tool but has limitations. It does not account for muscle mass, bone density, or fat distribution. Athletes, for example, may have a high BMI due to muscle, not fat. Always consult a doctor for a full health assessment.
What is a healthy BMI for adults?
For most adults, a BMI between 18.5 and 24.9 is considered healthy. However, healthy ranges can differ for older adults, children, and people of certain ethnic backgrounds.
Can BMI be different for men and women?
The same BMI scale is applied to both men and women, but body composition naturally differs between sexes. Women tend to have more body fat at the same BMI than men. A doctor can provide more personalized guidance.
How do I lower my BMI?
A combination of regular physical activity and a balanced, calorie-appropriate diet is the most effective approach. Small, sustainable changes tend to work better than extreme diets or exercise programs.