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BMI Calculator Tool
Calculate BMI from height and weight instantly. Compare with ideal, beauty, and model weights, JASSO/WHO classifications, body fat estimation, and BMI trend graph.
BMI
Please enter a value between 1 and 300 cm
Please enter a value between 0.1 and 500 kg
Please enter a value between 0 and 150
Results
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Please check your input values
JASSO (Japan)
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WHO
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Weight Comparison
| Type | BMI Standard | Weight | Difference |
|---|
Body Fat % (Estimated)
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* Estimated using the Deurenberg formula. For accurate measurement, use a body composition analyzer.
Results are approximate and not a medical diagnosis. Please consult a doctor or specialist for health decisions.
Reverse: Target BMI to Weight
BMI Trend History
How to Use
1
Enter height and weight
Enter your height (cm) and weight (kg). BMI is calculated in real-time. Age and gender are optional but enable body fat estimation and child index switching.
2
View results
See your BMI with a gauge, JASSO/WHO classification, and weight comparison table. Use reverse mode to find the weight needed for a target BMI.
3
Save records (optional)
Use the "Save Record" button in the BMI Trend History section to store your data. View your BMI trend as a line graph.
Average BMI by Age and Gender (Japan)
Average BMI values for Japanese adults based on the National Health and Nutrition Survey.
| Age Group | Male | Female |
|---|---|---|
| 20s | 23.1 | 21.0 |
| 30s | 24.2 | 21.6 |
| 40s | 24.4 | 22.2 |
| 50s | 24.5 | 22.7 |
| 60s | 24.0 | 23.0 |
| 70s | 23.5 | 23.1 |
* Approximate values.
About BMI Calculator
BMI (Body Mass Index) measures obesity based on height and weight. This tool provides JASSO and WHO classifications, weight comparisons, body fat estimation, and BMI trend tracking. All processing is done in your browser; no data is sent to servers.
Features
- Visual BMI GaugeSee your BMI on a color-coded semicircle gauge for instant visual feedback.
- Weight ComparisonCompare your weight with ideal, beauty, Cinderella, and model weights with difference display.
- BMI Trend TrackingSave measurement data and view your BMI trend as a line graph for diet progress tracking.
- Age-Based Index SwitchingAutomatically switches to Kaup Index (infants) or Rohrer Index (children) based on age input.
Use Cases
- Pre-health checkup BMI self-check
- Setting diet goals and tracking progress
- Checking beauty weight and Cinderella weight
- Evaluating child growth (Kaup/Rohrer Index)
- Reverse calculating weight for a target BMI
FAQ
What is BMI?
BMI (Body Mass Index) is calculated by dividing weight (kg) by height (m) squared. JASSO classifies BMI below 18.5 as underweight, 18.5-25 as normal, and 25+ as obese.
What is the BMI formula?
BMI = weight (kg) / height (m) squared. For example, 170cm and 65kg gives BMI = 65 / (1.70 * 1.70) = 22.49.
What is ideal weight?
Ideal weight is based on BMI 22, the value associated with the lowest disease risk. Formula: height (m) squared * 22.
What are beauty, Cinderella, and model weights?
Beauty weight (BMI 20) looks slim, Cinderella weight (BMI 18) is very thin, and model weight (BMI 17) is extremely thin. Weights below Cinderella increase health risks.
What are BMI limitations for muscular people?
BMI only uses height and weight, ignoring muscle mass. Muscular people may have high BMI but low body fat. Use a body composition analyzer for accuracy.
How is BMI evaluated for children?
Ages 0-5 use Kaup Index (same formula, different criteria). Ages 6-15 use Rohrer Index (weight/height^3*10^7). This tool switches automatically based on age.
What is the difference between body fat % and BMI?
BMI is a simple height/weight index. Body fat % measures actual fat content. This tool estimates body fat from BMI, age, and gender, which may differ from measured values.
Where are BMI records stored?
In your browser's local storage only. Nothing is sent to servers. Clearing browser data will also clear records.
How do Japanese and WHO BMI standards differ?
WHO defines obesity as BMI 30+, while JASSO uses BMI 25+ because Asians face higher health risks at lower BMI. This tool shows both standards.
Is my data safe?
Yes, all calculations happen in your browser. Your height and weight data are never sent to or stored on our servers. BMI history is stored only in your browser's local storage.