// Overview
WHAT IS THE BMI CALCULATOR?
BMI (Body Mass Index) is a widely used screening measure that estimates whether a person's body weight is appropriate for their height. It is calculated by dividing a person's weight in kilograms by the square of their height in metres. While BMI is not a diagnostic tool, it is a simple and useful first-step indicator of weight-related health risks.
For the Indian population, the WHO has recommended using slightly lower BMI cut-off values compared to Western populations, as Indians tend to have higher body fat percentage at lower BMI levels. The Indian-specific BMI categories are: Underweight (below 18.5), Normal (18.5–22.9), Overweight (23–27.4), and Obese (27.5+).
Regular BMI tracking is important because being significantly overweight or underweight is associated with serious health risks including diabetes, heart disease, hypertension, and nutritional deficiencies. Use this calculator periodically to monitor your weight status.
// Guide
HOW TO USE THIS TOOL
- Enter your height in centimetres — for example, 5 feet 7 inches = 170 cm.
- Enter your weight in kilograms — measure in the morning, without heavy clothing, for most accurate results.
- Click "Calculate BMI" — instantly see your BMI number and category.
To convert feet to cm: multiply feet by 30.48. For example, 5'7" = (5 × 30.48) + (7 × 2.54) = 152.4 + 17.78 = 170.18 cm ≈ 170 cm.
// Formula
THE FORMULA EXPLAINED
BMI = Weight (kg) ÷ Height² (m²)
Indian BMI Classification (WHO Asia-Pacific guidelines):
- Below 18.5 — Underweight
- 18.5 – 22.9 — Normal weight
- 23.0 – 27.4 — Overweight
- 27.5 and above — Obese
// Benefits
KEY BENEFITS
- Quick health snapshot: Understand your weight status in seconds, no medical equipment needed.
- India-specific categories: We use WHO Asia-Pacific BMI classifications, which are more appropriate for Indians.
- Free and private: Your height and weight data stays in your browser and is never stored.
- Track progress: Use regularly to monitor changes in your BMI over time.
- No app needed: Works directly in your phone browser.
// Use Cases
WHO USES THIS TOOL?
- Fitness enthusiasts tracking body composition progress
- People starting a diet or exercise programme
- Parents checking their children's healthy weight range
- Healthcare workers doing quick patient screening
- Students studying nutrition and public health
- Insurance applicants checking health eligibility criteria
// Pro Tips
TIPS & BEST PRACTICES
- BMI has limitations: It doesn't distinguish between muscle and fat mass. A muscular athlete may have a high BMI without being unhealthy. Always consult a doctor for a complete health assessment.
- Measure consistently: Weigh yourself at the same time of day (morning, before eating) for consistent tracking.
- Combine with waist circumference: A waist above 80 cm (women) or 90 cm (men) indicates abdominal obesity risk even at normal BMI.
- BMI for children is different: Children's BMI is age and gender-specific. Use pediatric BMI charts for anyone under 18.
// FAQ
FREQUENTLY ASKED QUESTIONS
What is a healthy BMI for Indians?
According to WHO Asia-Pacific guidelines, a healthy BMI for Indians is between 18.5 and 22.9. A BMI of 23 or above indicates overweight, and 27.5+ indicates obesity. These cut-offs are lower than Western standards because South Asians tend to have higher body fat at the same BMI.
Is BMI accurate for everyone?
BMI is a useful screening tool but has limitations. It may overestimate fat in muscular people (athletes, bodybuilders) and underestimate fat in older adults who have lost muscle mass. It doesn't account for fat distribution, which matters for health risk.
Can I use this BMI calculator for children?
No. Adult BMI categories don't apply to children. For children and teens (under 18), BMI is interpreted using age and sex-specific growth charts. Please consult a paediatrician for children's weight assessment.
What should I do if my BMI is high?
A high BMI is a signal to make lifestyle changes. Consult a doctor for personalised advice. Generally, a balanced diet, regular physical activity (150 min/week of moderate exercise), and adequate sleep help achieve healthy weight over time.
What is the ideal weight for my height?
You can calculate it from BMI: Ideal weight = 22 × height² (in metres). For example, for 170 cm: 22 × 1.70² = 22 × 2.89 = 63.6 kg.
// Related Tools
RELATED TOOLS YOU MAY LIKE