BMI Calculator
Calculate your BMI (Body Mass Index) instantly. Know if you are underweight, normal, overweight, or obese. Includes Asian BMI scale. Free, no signup required.
What is BMI Calculator?
The BMI (Body Mass Index) Calculator measures your body weight relative to your height to assess whether you are in a healthy weight range. It provides both WHO and Asian-specific BMI classifications.
Can I track my health metrics over time?
You can bookmark your results or save them as screenshots. The calculator provides instant results each time you use it.
Should I use this during pregnancy?
Pregnancy-related calculators provide general estimates. Always follow your gynecologist's specific guidance, as individual pregnancy journeys vary significantly.
How to Calculate BMI
- Enter your weight in kilograms (e.g. 70 kg)
- Enter your height in centimetres (e.g. 170 cm)
- Click Calculate to see your BMI value, health category, and personalised interpretation
How BMI Calculator is Calculated
BMI = Weight (kg) / Height² (m²). WHO classification: Underweight < 18.5, Normal 18.5–24.9, Overweight 25–29.9, Obese ≥ 30. Asian classification uses lower thresholds: Normal 18.5–22.9, Overweight 23–24.9, Obese ≥ 25.
Worked Example
For weight 70 kg and height 170 cm (1.70 m): BMI = 70 / (1.70)² = 70 / 2.89 = 24.2. This is Normal weight by WHO standard but Overweight by Asian standard.
Common Use Cases
- Health status assessment
- Weight management planning
- Fitness goal setting
- Medical screening reference
Common Mistakes to Avoid
- Using BMI as the sole health indicator — it cannot distinguish between muscle mass and fat. A muscular person may be classified as overweight despite low body fat.
- Applying adult BMI categories to children — children and teens use age-specific BMI percentiles, not the same thresholds.
- Ignoring the Asian BMI scale — people of South Asian descent face higher metabolic risk at lower BMIs (overweight starts at 23, not 25).
- Entering height in the wrong unit — make sure you are using centimetres, not inches or feet.
Frequently Asked Questions
What is a healthy BMI range?
A BMI of 18.5–24.9 is considered normal weight. For Asian populations, some experts suggest 18.5–22.9 due to higher metabolic risk at lower BMIs.
Is BMI accurate for everyone?
BMI has limitations — it does not distinguish between muscle and fat. Athletes may show "overweight" BMI despite low body fat. It is less accurate for children, the elderly, and pregnant women.
How can I improve my BMI?
For overweight: reduce caloric intake by ~500 cal/day and exercise 150 min/week. For underweight: increase intake with nutrient-dense foods and add strength training.
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Why You Need This Calculator
BMI remains the most widely used screening tool for weight-related health risks. For Indians and South Asians, standard WHO cutoffs can be misleading. Research shows South Asians develop type 2 diabetes and cardiovascular disease at lower BMI levels. Asian BMI classification uses lower thresholds: overweight at 23 (not 25) and obesity at 25 (not 30).
Calculator Features
- Instant BMI with WHO and Asian classifications
- Color-coded health risk categories
- Ideal weight range based on height
- Personalized health interpretation
- Works offline — no data transmitted
- Healthy range in kg and pounds
The Math Behind It
BMI = Weight (kg) / [Height (m)]². Classification: <18.5 Underweight, 18.5-22.9 Normal (Asian), 23-24.9 Overweight (Asian), ≥25 Obese (Asian).
Calculation Example
Weight 75 kg, Height 170 cm (1.70 m): BMI = 75 / (1.70)² = 75 / 2.89 = 25.95. WHO: Overweight. Asian: Obese Class I. Ideal weight for 170 cm: 53.5-66.2 kg (Asian scale).
Quick Reference
BMI classification: WHO vs Asian cutoffs
| Category | WHO Range | Asian Range | Risk |
|---|---|---|---|
| Underweight | < 18.5 | < 18.5 | Nutritional deficiency |
| Normal | 18.5 – 24.9 | 18.5 – 22.9 | Low |
| Overweight | 25.0 – 29.9 | 23.0 – 24.9 | Moderate |
| Obese I | 30.0 – 34.9 | 25.0 – 29.9 | High |
| Obese II | 35.0+ | 30.0+ | Very high |
Pro Tips & Expert Insights
- 💡 For Indians, use the Asian BMI scale — it accounts for higher metabolic risk at lower weights.
- 💡 Combine BMI with waist circumference for a complete picture.
- 💡 A 5–10% weight reduction significantly reduces cardiovascular risk if overweight.
- 💡 Athletes should use body fat percentage instead — muscle weighs more than fat.
- 💡 Measure weight at the same time each day for consistency.
Who Benefits From This?
Health-conscious individuals, doctors during assessments, fitness enthusiasts, and insurance companies for risk evaluation.
📚 Complete Guide Available
Want to learn more? Read our comprehensive guide with detailed explanations, real-world examples, expert analysis, and actionable tips.
Read: BMI Chart India 2026: Are You in Healthy Range?Medical disclaimer: This calculator provides general estimates and is not a substitute for professional medical advice, diagnosis, or treatment. Results may vary based on individual factors. Consult a healthcare professional for personalized guidance. See our full Disclaimer.
Methodology: Based on clinically validated formulas used in nutrition and medical research. See our Editorial Policy for how we validate content.
Maintained by: Sagar Sahni, Calc Labz | Review: formula checks, worked examples, and periodic updates
Need a correction? Contact us with the calculator name, your inputs, and the issue you found.
Last updated: April 2026