Shows your BMI, ideal weight, and obesity classification.
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Calculation basis and official references
Reviewed on:
This calculator is not a diagnosis, treatment plan, or prescription. Please consult a qualified clinician about your medical decisions.
Formula basis
BMI = weight (kg) / height (m)^2. Ideal weight (kg) = height (m)^2 x 22. Difference from ideal weight (kg) = weight - ideal weight (shown with a plus sign when the result is zero or positive). Classification: BMI < 18.5 underweight, 18.5 to <25 normal range, 25 to <30 obesity class 1, 30 to <35 obesity class 2, 35 to <40 obesity class 3, 40 and above obesity class 4.
Calculation method
Calculates BMI from height and weight, classifies it into the six-tier scale used by the Japan Society for the Study of Obesity (underweight to obesity class 4), and shows the ideal weight and the difference from it based on BMI 22, the value associated with the lowest statistical disease risk.
Exclusions and checks required
BMI cannot distinguish body fat from muscle mass, so muscular individuals may have their obesity level overestimated.
This formula does not apply to children or adolescents who are still growing.
Not intended as a weight-management guide during pregnancy.
Example input:：A person 170 cm tall weighing 65 kg
height
170
weight
65
The BMI is about 22.49 and the ideal weight is about 63.58 kg, but individual results vary with body composition, muscle mass, and age.
Shows your BMI, ideal weight, and obesity classification.
What values should I enter?
Applies to: Body & metabolism
How should I interpret this estimate?
Calculates BMI from height and weight, classifies it into the six-tier scale used by the Japan Society for the Study of Obesity (underweight to obesity class 4), and shows the ideal weight and the difference from it based on BMI 22, the value associated with the lowest statistical disease risk.
How to use
Enter your input values and press Calculate.
Review the result and compare it with expected context.
BMI = weight (kg) / height (m)^2. Ideal weight (kg) = height (m)^2 x 22. Difference from ideal weight (kg) = weight - ideal weight (shown with a plus sign when the result is zero or positive). Classification: BMI < 18.5 underweight, 18.5 to <25 normal range, 25 to <30 obesity class 1, 30 to <35 obesity class 2, 35 to <40 obesity class 3, 40 and above obesity class 4.