BMI Calculator: What Is a Healthy BMI & How to Improve It

What is BMI?

Body Mass Index (BMI) is a numerical measure of body fat based on height and weight. It's used by doctors worldwide as a quick screening tool — not a perfect diagnostic measurement.

BMI Formula

BMI = Weight (kg) ÷ Height² (m)

Example: 70 kg, 1.75 m tall
BMI = 70 ÷ (1.75 × 1.75) = 22.9 → Normal weight

BMI Categories (WHO Standard)

• Below 18.5 — Underweight
• 18.5–24.9 — Normal weight ✅
• 25.0–29.9 — Overweight
• 30.0–34.9 — Obese (Class I)
• 35.0–39.9 — Obese (Class II)
• 40+ — Severely Obese (Class III)

Why BMI Has Limitations

BMI doesn't differentiate between muscle and fat. Athletes with high muscle mass may show "overweight" BMI. Indian populations tend to have higher body fat at lower BMIs — many health guidelines recommend a BMI target of 18–23 for South Asians.

How to Improve Your BMI

• Caloric deficit of 300–500 kcal/day for gradual weight loss
• Strength training 3x/week to build lean muscle
• Reduce refined carbs, increase protein intake
• 7–9 hours sleep (poor sleep increases cortisol → fat storage)

Calculate your BMI instantly with our free BMI Calculator →