| Measurement date | Weight | BMI | Classification | Record action |
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Free BMI Calculator
A free tool that instantly calculates your body mass index (BMI), an underweight/normal/overweight/obese assessment, and the healthy weight range for your height from just your height and weight. All calculations happen in your browser, so the values you enter are never sent anywhere.
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The profile and measurements are stored only on this device and are not sent to the server.
Enter your height and weight and press Calculate to see the results.
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Healthy weight range
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Standard weight (BMI 22)
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Difference from standard
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Formula: weight (kg) ÷ height (m)²
This is an adult screening reference. Children and adolescents need age-specific growth standards; during pregnancy or with high muscle mass, do not judge health from BMI alone.
Measurement trend
Review weight and BMI changes in measurement-date order.
No measurements have been saved yet.
How to use
- Enter your height (cm) and weight (kg).
- Press "Calculate" to see your BMI and obesity assessment.
- You can also see the healthy weight range and standard weight for your height.
Calculation basis and verification sources
The formula is BMI = weight (kg) ÷ height (m)². The Korean adult option classifies below 18.5 as underweight, 18.5–22.9 as normal, 23–24.9 as pre-obesity, and 25 or above as obesity; its detailed stages follow the KSSO eighth edition. The WHO adult classification is a separate option.
Standards checked: 2026-08-07. Both classifications are adult screening references, not diagnostic criteria for children, adolescents, pregnancy, edema, or people with high muscle mass. Do not set treatment or weight-loss targets from this result alone.
Frequently asked questions
How is BMI calculated?
BMI is your weight in kilograms divided by the square of your height in meters. For example, at 170 cm and 68 kg, it is 68 ÷ (1.7 × 1.7) = about 23.5.
What is the normal BMI range?
The Korean Society for the Study of Obesity considers 18.5–22.9 normal for Korean adults, while the WHO adult standard uses 18.5–24.9. You can choose the standard on this page.
Are the height and weight I enter sent to a server?
No. All calculations happen inside your browser, and the values you enter are not sent to any external server.
This result is for general reference only and does not replace medical diagnosis or advice. Consult a professional for health-related decisions.