BMI Calculator
Enter your height and weight to calculate BMI, category, and healthy weight range instantly.
How BMI Calculation Works
BMI calculation uses a direct formula: weight in kilograms divided by height in meters squared. Formula: BMI = weight / (height × height). For example, if a person is 70 kg and 1.75 m, BMI is about 22.9. This falls into the normal range for most adult interpretations. The page is built to satisfy common search intent like “how to calculate BMI”, “BMI calculation method”, and “BMI examples”.
A BMI calculator is useful for trend tracking, not final diagnosis. It helps in nutrition planning, weight management, and baseline health assessment. Better decisions come from repeated measurements under similar conditions, then observing direction over time instead of reacting to one isolated value.
BMI Categories and Interpretation
- Below 18.5: Underweight
- 18.5 to 24.9: Normal
- 25.0 to 29.9: Overweight
- 30.0 and above: Obesity
These ranges align with WHO guidance for adults. The tool also shows healthy weight range and center ideal value for practical planning.
Examples of BMI Calculation
- 160 cm, 52 kg: BMI ≈ 20.3 (normal)
- 180 cm, 92 kg: BMI ≈ 28.4 (overweight)
- 170 cm, 105 kg: BMI ≈ 36.3 (obesity)
These examples are useful for validating manual calculations and comparing category boundaries.
Frequently Asked Questions
Does BMI alone define ideal health?
No. BMI is a screening signal and should be interpreted with body composition, age, and clinical context.
Is BMI valid for children?
Children and teens require age and sex percentile charts; adult BMI interpretation is different.
How often should I track BMI?
Weekly or biweekly measurement intervals are usually more useful than daily tracking.
References and Trust Notes
Last technical review date: March 26, 2026.