BMI Calculator

Calculate your Body Mass Index and know your ideal weight

BMI Chart & Categories

Underweight: BMI less than 18.5
You may need to gain weight for optimal health
Normal (Healthy): BMI 18.5 - 24.9
Perfect! Maintain your current lifestyle
Overweight: BMI 25 - 29.9
Consider healthy diet and exercise
Obese: BMI 30 and above
Consult a healthcare professional for guidance

What is BMI (Body Mass Index)?

BMI (Body Mass Index) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in metres squared.

BMI is an inexpensive and easy screening method for weight category - underweight, healthy weight, overweight, and obesity. BMI does not measure body fat directly, but BMI is moderately correlated with more direct measures of body fat.

How to Calculate BMI Manually?

Formula: BMI = Weight (kg) / [Height (m)]²

Example: For a person weighing 70 kg and height 1.70 m (170 cm):
BMI = 70 / (1.70 × 1.70) = 70 / 2.89 = 24.2

BMI Limitations

  • May overestimate body fat in athletes and others who have muscular build
  • May underestimate body fat in older persons and others who have lost muscle
  • Not suitable for pregnant women, children under 18, and professional athletes

Ideal Weight Range for Indians

According to Indian Council of Medical Research (ICMR), the ideal BMI range for Indians is 18.5 to 23.0, slightly lower than the international standard of 18.5 to 24.9, as Indians tend to have more body fat at lower BMI levels.

What is BMI Calculator?

BMI (Body Mass Index) Calculator is a free health tool that measures your body mass relative to your height and weight. It's the most common method used worldwide to classify whether a person is underweight, normal weight, overweight, or obese.

Developed by Adolphe Quetelet in the 19th century, BMI provides a quick screening tool to identify potential weight problems in adults. While it doesn't directly measure body fat, it correlates strongly with health risks associated with being under or overweight.

How is BMI Calculated?

The BMI formula is simple:

BMI = Weight (kg) / [Height (m)]²

BMI Categories:

BMI Range Category Health Risk
Below 18.5 Underweight Nutrient deficiency, weak immunity
18.5 - 24.9 Normal Low risk - Ideal weight range
25 - 29.9 Overweight Increased risk of diseases
30 and above Obese High risk - requires medical attention

Frequently Asked Questions (FAQs)

A BMI between 18.5 and 24.9 is considered healthy for most adults. This range is associated with the lowest health risks and optimal body functioning. However, BMI recommendations may vary slightly based on ethnicity and age.

BMI has limitations. It doesn't distinguish between muscle and fat mass, so athletes or bodybuilders may have high BMI despite low body fat. It's also less accurate for elderly, pregnant women, and children. Use it as a screening tool, not definitive diagnosis.

To reduce BMI: (1) Create calorie deficit through balanced diet, (2) Exercise 30-60 minutes daily (cardio + strength training), (3) Sleep 7-8 hours, (4) Manage stress, (5) Drink 2-3 liters water daily, (6) Avoid processed foods and sugary drinks. Aim for 0.5-1 kg weight loss per week.

For Asian populations including Indians, BMI cutoffs are lower. Overweight is BMI ≥ 23 and obesity is BMI ≥ 27.5 as per WHO Asia-Pacific guidelines. Indians have higher body fat percentage at same BMI compared to Caucasians, increasing disease risk.

High BMI (≥30) is associated with increased risk of type 2 diabetes, heart disease, high blood pressure, stroke, certain cancers, and joint problems. Low BMI (<18.5) can indicate malnutrition, osteoporosis, and weakened immunity. However, BMI is just one indicator among many.

No, this calculator is for adults (18+ years). Children and teens should use age and gender-specific BMI-for-age percentile charts as their body composition changes during growth. Consult a pediatrician for children's BMI assessment.

Benefits of Maintaining Healthy BMI

Heart Health: Reduces risk of cardiovascular diseases by 40-50%.
Diabetes Prevention: Lowers type 2 diabetes risk significantly.
Better Mobility: Easier movement and reduced joint pain.
Mental Health: Improved mood, confidence, and energy levels.

Important Note

BMI is a screening tool, not a diagnostic of body fatness or health. For complete health assessment, consult healthcare professionals who may measure waist circumference, skin-fold thickness, body composition, family history, and other factors.

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