BMI Calculator Online – Assess Your Health

Enter your height, weight, age, and gender to instantly calculate your Body Mass Index and get a full breakdown of your health category and ideal weight range.

What Is BMI?

Body Mass Index (BMI) is a numerical value derived from a person’s height and weight. It is widely used as a screening tool to categorize individuals into health ranges — underweight, normal weight, overweight, or obese. While BMI does not directly measure body fat, it provides a quick and useful indicator of whether a person’s weight may be putting their health at risk.

BMI Formula

For metric measurements, BMI is calculated as weight in kilograms divided by height in meters squared.

For imperial measurements, BMI is calculated as weight in pounds multiplied by 703, then divided by height in inches squared.

BMI Categories

Underweight — BMI below 18.5 Normal Weight — BMI between 18.5 and 24.9 Overweight — BMI between 25.0 and 29.9 Obese — BMI of 30.0 and above

How to Use This Calculator

1. Select your unit system — choose Metric (cm, kg) or Imperial (inches, lbs) from the dropdown menu.
2. Enter your height — type your height in centimetres or inches, including decimals if needed (e.g., 170.5 cm).
3. Enter your weight — type your weight in kilograms or pounds (e.g., 70.2 kg or 154 lbs).
4. Enter your age — type your current age in years.
5. Select your gender — choose Male or Female from the dropdown.
6. Click “Calculate” — your BMI result and full breakdown appear instantly.
7. Review your results — see your BMI score, health category, recommended weight range, and a complete BMI reference table based on your height.

What the Results Include

BMI Score Your calculated Body Mass Index value, rounded to two decimal places for accuracy.

Health Category Your result is classified as underweight, normal weight, overweight, or obese based on standard WHO guidelines.

Optimal Weight Range The calculator shows the weight range that corresponds to a healthy BMI (18.5–24.9) for your specific height, giving you a practical target to work toward if needed.

Full BMI & Weight Range Table A detailed reference table showing all BMI categories, their BMI ranges, and the corresponding weight ranges for your height — displayed automatically after every calculation.

Why Use This BMI Calculator?

Metric & Imperial Support Switch freely between metric and imperial units. The calculator converts automatically, so your results are always accurate regardless of the unit system you prefer.

Decimal Input Supported Enter precise measurements like 170.5 cm or 70.2 kg without rounding — useful when accuracy matters.

Personalized Results Age and gender are factored into the context of your results, giving you a more relevant health picture.

Comprehensive Output Rather than just showing a number, this calculator provides your category, ideal weight range, and a full reference table — all in one place.

Free & Instant No registration or payment required. Just enter your details and get your results in seconds.

Important Note

BMI is a useful general indicator but does not account for muscle mass, bone density, body composition, or fat distribution. It should be used as one of several tools when assessing overall health, and not as a standalone medical diagnosis. If you have concerns about your weight or health, consult a qualified healthcare professional.