BMI Calculator
⚖️ BMI Calculator
Calculate your Body Mass Index instantly. Check if you are underweight, normal, overweight or obese.
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Minimal |
| 18.5 - 24.9 | Normal Weight | Low |
| 25.0 - 29.9 | Overweight | Increased |
| 30.0 - 34.9 | Obese Class I | High |
| 35.0 - 39.9 | Obese Class II | Very High |
| 40.0 and above | Obese Class III | Extremely High |
What is BMI?
BMI (Body Mass Index) is a measurement that uses your height and weight to estimate how much body fat you have. It is a widely used screening tool to identify whether a person is underweight, normal weight, overweight, or obese.
BMI is calculated by dividing your weight in kilograms by the square of your height in meters. For example, if you weigh 70 kg and are 1.75 m tall, your BMI is 70 divided by (1.75 x 1.75) = 22.9.
What the BMI Categories Actually Mean
Each BMI range on the scale above corresponds to a general health screening category used by doctors and health organizations worldwide. A BMI under 18.5 suggests you may not have enough body reserves, which can affect energy levels and immune function. The 18.5–24.9 "normal" range is statistically associated with the lowest average health risk across large populations. Ranges above 25 are linked with progressively higher risk of conditions like type 2 diabetes, high blood pressure, and heart disease — though risk varies significantly by individual factors like fitness level, fat distribution, and family history.
Because BMI is a population-level screening tool rather than a diagnostic one, it works best as a starting point for a conversation with a healthcare provider rather than a definitive verdict on your health.
How to Use BMI Calculator
- Step 1: Choose Metric (kg, cm) or Imperial (lbs, ft) units.
- Step 2: Enter your weight and height.
- Step 3: Optionally enter your age and gender.
- Step 4: Click Calculate BMI to see your result.
- Step 5: Check the BMI scale and category table.
What This Calculator Gives You Beyond the Number
- Visual scale marker: See exactly where your BMI falls on the underweight-to-extreme spectrum at a glance.
- Full category reference table: Compare your result against all six BMI classifications side by side.
- Personalized tip cards: Get a set of practical next-step suggestions matched to your specific category, not generic advice.
- Metric and Imperial support: Switch units instantly without needing to manually convert kg to lbs or cm to feet.
Related Reading
Want a deeper dive into what your number means and its limitations? Read our full guide: How to Calculate Your BMI and What It Actually Means. You might also find our Age Calculator useful.