BMI Calculator (Body Mass Index)
Body Mass Index (BMI) is a measure used to assess weight relative to height, calculated by dividing weight in kg by height in meters squared (kg/m²).
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Categories use the standard adult BMI cut-offs used internationally | WeightBMI
BMI Classification Table (WHO Standards)
The World Health Organization (WHO) uses this classification to determine healthy weight for adults (men and women) over 18 years old.
| Category | BMI Range |
|---|---|
| Severe Underweight | Below 16 |
| Underweight | 16 – 18.4 |
| Healthy Weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obesity Class I | 30 – 34.9 |
| Obesity Class II | 35 – 39.9 |
| Obesity Class III | 40 or above |
Ideal Weight by Height
WeightBMI Health Toolkit
BMI Calculation
Calculate your Body Mass Index instantly from height and weight.
Ideal Weight Analysis
Estimate a healthy weight range for your height using the BMI range and common formulas.
Daily Calorie Needs
Determine your TDEE and daily calories needed to reach your target weight.
Exercise Calorie Tracker
Estimate calories burned across 30 common activities using MET values.
Goal Progress Tracker
Monitor your weight trends and stay motivated throughout your journey.
Personalized Insights
Get smart health recommendations tailored to your specific BMI category.
Understanding BMI Results
Body Mass Index (BMI) is a vital metric used by health professionals to assess body composition. WeightBMI ensures your results are calculated using the latest WHO and CDC standards.
WeightBMI Expert Tip
"While BMI is an excellent screening tool, combining it with activity tracking provides a more comprehensive view of your wellness."
Frequently Asked Questions
?What is a healthy BMI for my age and gender?
For adults over 20, a healthy BMI is between 18.5 and 24.9. This standard applies to both men and women. However, older adults (65+) may benefit from a slightly higher BMI (up to 27) for better health protection according to recent studies.
?How is BMI calculated?
BMI is calculated by dividing your weight in kilograms by your height in meters squared (kg/m²). For example: a person weighing 70 kg and 1.75 m tall has BMI = 70 ÷ (1.75 × 1.75) = 22.9. Our tool supports both metric and imperial units.
?What are the WHO BMI categories?
The World Health Organization (WHO) classifies BMI as: Underweight (<18.5), Normal weight (18.5–24.9), Overweight (25–29.9), Obesity Class I (30–34.9), Obesity Class II (35–39.9), and Obesity Class III (≥40).
?How accurate is the BMI calculator for athletes?
BMI can overestimate body fat in athletes with high muscle mass because muscle is denser than fat. In these cases, use our BMI calculator alongside the body fat percentage calculator for a more complete picture.
?How do I calculate my ideal weight?
Ideal weight is estimated with several formulas. Our ideal weight calculator uses the Hamwi, Devine, Robinson, and Miller formulas to give you a comprehensive healthy weight range based on your height and gender.
Master Your Health with WeightBMI
Use our free calculators to understand your numbers and plan realistic next steps.
Calculations use published formulas and the standard adult BMI categories. They do not replace medical advice.