BMI Calculator 2025

Body Mass Index & Health Assessment

💪 Advanced BMI Calculator

WHO Standard Categories - 8 detailed classifications

BMI Prime Calculator - Optimal health indicator

India-Specific - Adjusted for Asian genetics

Healthy Weight Range - Personalized targets

Enter Your Details

Your Results

Your BMI

24.2

Normal

WHO Category

Normal

Low Risk

BMI Prime

0.97

Below ideal

🇮🇳 India-Specific Category:

OverweightMedium Risk

Adjusted for Asian population genetics

💚 Healthy Weight Range:

Minimum:53.5 kg
Maximum:72.2 kg
Ideal Weight:62.9 kg

BMI Categories (WHO Standard)

CategoryBMI RangeBMI PrimeRisk Level
Severe Thinness0 - 160.00 - 0.64Very High Risk
Moderate Thinness16 - 170.64 - 0.68High Risk
Mild Thinness17 - 18.50.68 - 0.74Moderate Risk
Normal18.5 - 250.74 - 1.00Low Risk
Overweight25 - 301.00 - 1.20Moderate Risk
Obese Class I30 - 351.20 - 1.40High Risk
Obese Class II35 - 401.40 - 1.60Very High Risk
Obese Class III40 - 40+1.60 - 1.6+Extremely High Risk

Your Position on BMI Scale

24.2

What is BMI (Body Mass Index)?

BMI (Body Mass Index) is a measure of body fat based on height and weight. It's calculated using the formula: BMI = weight (kg) / height² (m²). BMI helps assess if you're underweight, normal weight, overweight, or obese.

Our calculator uses WHO standards with 8 categories (from Severe Thinness to Obese Class III) and includes India-specific BMI ranges adjusted for Asian population genetics, plus BMI Prime calculation for optimal health assessment.

How to Use

  1. 1Select your unit system (Metric or Imperial)
  2. 2Choose your gender (Male or Female)
  3. 3Enter your age in years
  4. 4Input your current weight and height
  5. 5Get instant BMI, category, and health insights

BMI Calculation Formula

📐 Metric Formula

BMI = weight (kg) ÷ [height (m)]²

Or: weight (kg) ÷ [height (cm) ÷ 100]²

Example:

Weight: 70 kg

Height: 170 cm (1.7 m)

BMI = 70 ÷ (1.7)² = 70 ÷ 2.89

BMI = 24.2 (Normal Weight)

📏 Imperial Formula

BMI = [weight (lbs) ÷ height (in)²] × 703

703 is the conversion factor

Example:

Weight: 154 lbs

Height: 5'7" (67 inches)

BMI = (154 ÷ 67²) × 703

BMI = 24.1 (Normal Weight)

BMI Categories: WHO vs India

🌍 WHO Standard

< 16Severe Thinness
16 - 17Moderate Thinness
17 - 18.5Mild Thinness
18.5 - 25Normal Weight
25 - 30Overweight
30 - 35Obese Class I
35 - 40Obese Class II
> 40Obese Class III

🇮🇳 India-Specific (Asian)

Why different? Asian populations have higher body fat percentage at lower BMI compared to Caucasians. Indian standards are adjusted accordingly.

< 18Underweight

High Risk

18 - 22.9Normal Weight

Low Risk

23 - 24.9Overweight

Medium Risk

25 - 29.9Obese Class I

High Risk

≥ 30Obese Class II

Very High Risk

What is BMI Prime?

BMI Prime is a ratio of your actual BMI to the upper limit of normal BMI (25). It's a dimensionless number that makes BMI easier to interpret.

Formula:

BMI Prime = BMI ÷ 25

Interpretation:

BMI Prime < 0.74: Underweight
BMI Prime = 0.74-1.0: Normal (Ideal)
BMI Prime = 1.0-1.2: Overweight
BMI Prime > 1.2: Obese

Example: If your BMI is 30, your BMI Prime is 30÷25 = 1.2 (indicates obesity)

Health Implications by BMI Range

Underweight (BMI < 18.5)

Health Risks:

  • Weakened immune system
  • Osteoporosis risk
  • Anemia and fatigue
  • Fertility issues

Normal Weight (BMI 18.5-24.9)

Benefits:

  • Lower risk of chronic diseases
  • Better energy levels
  • Optimal metabolic function
  • Improved quality of life

Overweight (BMI 25-29.9)

Health Risks:

  • Increased risk of type 2 diabetes
  • High blood pressure
  • Joint problems
  • Sleep apnea

Obese (BMI ≥ 30)

Serious Health Risks:

  • Heart disease and stroke
  • Type 2 diabetes
  • Certain cancers
  • Liver disease
  • Reduced life expectancy

Frequently Asked Questions

1. What is a healthy BMI range?

A healthy BMI range is 18.5 to 24.9 according to WHO standards. However, for Asian populations (including India), the healthy range is slightly lower at 18.0 to 22.9.

Underweight: BMI less than 18.5

Normal: BMI 18.5-24.9 (WHO) or 18.0-22.9 (Asia)

Overweight: BMI 25-29.9 (WHO) or 23-24.9 (Asia)

Obese: BMI 30 and above (WHO) or 25+ (Asia)

2. Is BMI accurate for everyone?

BMI is a useful screening tool but has limitations. It doesn't distinguish between muscle and fat mass, so it may:

❌ Not Accurate For:

  • Athletes & bodybuilders: High muscle mass = higher BMI
  • Elderly: May lose muscle mass, lower BMI
  • Pregnant women: Weight gain is normal
  • Children: Need age & gender-specific charts

✅ Good Indicator For:

  • General adult population
  • Initial health screening
  • Tracking weight trends

3. How to improve your BMI if it's unhealthy?

🔻 To Lower BMI (Overweight/Obese):

Diet: Calorie deficit (500-1000 cal/day), balanced nutrition

Exercise: 150-300 min/week cardio + strength training

Target: Lose 0.5-1 kg per week safely

Hydration: Drink 3-4 liters water daily

Sleep: 7-8 hours nightly for hormonal balance

🔺 To Increase BMI (Underweight):

Diet: Calorie surplus (300-500 cal/day), protein-rich

Exercise: Strength training to build muscle

Target: Gain 0.25-0.5 kg per week

Meals: 5-6 smaller meals throughout day

Nutrients: Focus on healthy fats & complex carbs