Your BMI
Underweight
<18.5Normal
18.5–25Overweight
25–30Obese
>30
<18.5Normal
18.5–25Overweight
25–30Obese
>30
⚖️ How the BMI Calculator Works
Body Mass Index (BMI) is a simple screening tool developed by Adolphe Quetelet in 1832. It estimates body fat based on height and weight and is used worldwide by health organizations.
BMI (metric) = weight (kg) / height² (m)
BMI (imperial) = 703 × weight (lb) / height² (in)
1
Convert height to metres (or inches for imperial). Square it.
2
Divide weight by the squared height. The result is your BMI score.
3
Compare the score against WHO categories: Underweight <18.5 · Normal 18.5–24.9 · Overweight 25–29.9 · Obese ≥30.
Worked Example: 70 kg, 175 cm tall.
Height in metres = 1.75 m | Height² = 3.0625
BMI = 70 / 3.0625 = 22.86 → Normal weight ✅
Height in metres = 1.75 m | Height² = 3.0625
BMI = 70 / 3.0625 = 22.86 → Normal weight ✅
BMI is a screening tool, not a diagnostic. Consult a healthcare professional for a full assessment.