BMI Calculator
Calculate your Body Mass Index, health category, ideal weight range, and BMI Prime instantly. Supports both metric and imperial units.
Your Measurements
kg
cm
| Category | BMI Range |
|---|---|
Underweight | < 18.5 |
Normal weight | 18.5 – 24.9 |
Overweight | 25 – 29.9 |
Obese | ≥ 30 |
Your BMI
24.2
NormalBMI Scale
Underweight
Normal
Overweight
Obese
0
18.5
25
30
40+
BMI Prime
0.97
ratio to upper normal (25)
Ideal Weight
53.5–72.3
kg for normal BMI
BMI is a screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, or fat distribution. Consult a healthcare professional for a comprehensive health assessment.
Frequently Asked Questions
- Is the BMI Calculator free?
- Yes, 100% free. No account required, no data uploaded, no limits.
- What is a healthy BMI?
- A BMI between 18.5 and 24.9 is considered normal weight for most adults. Below 18.5 is underweight, 25–29.9 is overweight, and 30 or above is obese according to WHO classification.
- What is BMI Prime?
- BMI Prime is the ratio of your BMI to the upper limit of the normal range (25). A BMI Prime of 1.0 means you are exactly at the top of the normal range. Below 0.74 is underweight, 0.74–1.0 is normal, and above 1.0 is overweight or obese.
- Does BMI work for athletes and muscular people?
- BMI does not distinguish between fat and muscle mass. Highly muscular individuals may have a high BMI but low body fat. It is a population-level screening tool and should be interpreted alongside other measures such as waist circumference and body fat percentage.
- How is BMI calculated?
- BMI = weight (kg) ÷ height² (m²). For imperial units, the formula is BMI = 703 × weight (lbs) ÷ height² (inches²). The calculator converts imperial inputs to metric before computing.
- Does it work on mobile?
- Yes, it works on all modern browsers including mobile Safari and Chrome on iOS and Android.