BMI Calculator

BMI is calculated by dividing your weight in kilograms by your height in meters squared. Formula: BMI = weight (kg) / height (m)². For imperial units, multiply weight in pounds by 703, then divide by height in inches squared: BMI = (weight × 703) / height². For example, a person who weighs 70 kg and is 1.75 m tall has a BMI of 70 / (1.75)² = 22.9.

BMI categories are: Underweight (below 18.5) – may indicate malnutrition or other health issues; Normal weight (18.5-24.9) – associated with lowest health risks; Overweight (25-29.9) – increased risk of health problems; Obese (30+) – significantly higher risk of diabetes, heart disease, and other conditions. These ranges are general guidelines and may vary based on age, gender, and ethnicity.

BMI has limitations. It doesn't distinguish between muscle and fat, so athletes with high muscle mass may have a 'overweight' BMI despite being healthy. It also doesn't account for fat distribution—belly fat is riskier than fat elsewhere. BMI may be less accurate for elderly people (who lose muscle mass), children (who are still growing), and certain ethnic groups. Consider BMI alongside other measures like waist circumference and body fat percentage.

For adults, a healthy BMI is generally between 18.5 and 24.9. Within this range, health risks are typically lowest. However, optimal BMI can vary: some research suggests slightly higher BMI (23-25) may be better for older adults, while Asian populations may face health risks at lower BMIs (23+). Your ideal weight should also consider factors like muscle mass, bone density, and overall fitness level.

To reach a healthier BMI: If overweight, create a moderate calorie deficit through diet and exercise—aim to lose 0.5-1 kg (1-2 lbs) per week. Focus on whole foods, lean proteins, and vegetables while limiting processed foods and sugars. If underweight, increase calorie intake with nutrient-dense foods and strength training to build muscle. Always consult a healthcare provider before starting any weight management program, especially if you have underlying health conditions.