Learn how to calculate your BMI, understand what it means for your health, and discover the healthy BMI ranges for different age groups.
Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. It's one of the most commonly used screening tools to identify whether a person has a healthy weight relative to their height. BMI is calculated using a simple formula that divides weight in kilograms by height in meters squared.
While BMI is not a perfect measure (it doesn't account for muscle mass or bone density), it remains a useful screening tool for identifying potential health risks associated with being underweight, overweight, or obese. Healthcare professionals worldwide use BMI as a starting point for assessing overall health.
BMI = Weight (kg) ÷ Height (m)²
BMI = [Weight (lbs) ÷ Height (inches)²] × 703
Example:
Weight: 70 kg, Height: 1.75 m
BMI = 70 ÷ (1.75 × 1.75) = 70 ÷ 3.06 = 22.9 (Normal weight)
Being underweight may indicate malnutrition or other health issues. It can increase the risk of bone loss, weakened immune function, and nutritional deficiencies. Consult a healthcare provider if your BMI is in this range.
This is the healthy weight range for most adults. Maintaining a BMI in this range is associated with lower risk of chronic diseases like heart disease, diabetes, and certain cancers. Focus on maintaining healthy habits.
Being overweight increases the risk of developing health problems including heart disease, type 2 diabetes, and high blood pressure. Lifestyle changes like diet and exercise can help achieve a healthier weight.
Obesity significantly increases the risk of serious health conditions including heart disease, stroke, type 2 diabetes, and certain cancers. Consult a healthcare provider for personalized guidance and support.
| Height | Normal (18.5-24.9) | Overweight (25-29.9) | Obese (30+) |
|---|---|---|---|
| 5'0" (152 cm) | 97-127 lbs | 128-153 lbs | 154+ lbs |
| 5'4" (163 cm) | 110-145 lbs | 146-174 lbs | 175+ lbs |
| 5'8" (173 cm) | 122-164 lbs | 165-197 lbs | 198+ lbs |
| 6'0" (183 cm) | 136-184 lbs | 185-221 lbs | 222+ lbs |
Use our free BMI calculator to instantly determine your body mass index and get personalized health insights.
BMI is a useful screening tool but not perfect. It may overestimate body fat in muscular individuals and underestimate it in older adults with reduced muscle mass.
BMI is based on height and weight only, while body fat percentage measures the actual proportion of fat in your body. Body fat percentage is more accurate but harder to measure.
Checking your BMI monthly or quarterly is reasonable for tracking weight changes. More frequent checks aren't necessary as weight naturally fluctuates daily.
Consult a healthcare provider for personalized advice. They can assess your overall health and recommend appropriate lifestyle changes or medical interventions.