Health calculator
Standalone tool pageBMI Calculator
Estimate body mass index from height and weight, with a general category label.
Result
BMI
General category
How It Works
BMI = weight in kilograms divided by height in meters squared. It is a broad screening estimate that compares body weight to height. BMI can be useful for population-level categories, but it does not measure body fat, muscle mass, pregnancy, age-related changes, or individual medical risk.
Example
A person who is 170 cm tall and weighs 70 kg has BMI = 70 ÷ 1.70² = 24.2, which falls in the general normal range category for many adult BMI charts.
BMI category context
- Under 18.5 is commonly labeled underweight.
- 18.5 to under 25 is commonly labeled normal range.
- 25 to under 30 is commonly labeled overweight.
- 30 and above is commonly labeled obesity range.
Important limitations
- BMI does not distinguish fat mass from muscle mass.
- BMI does not account for age, sex, ethnicity, pregnancy, or health conditions.
- BMI is not a diagnosis and should not replace professional care.
- Use consistent measurements if tracking changes over time.
Frequently Asked Questions
Is BMI accurate for everyone?
No. It may not reflect body composition for athletes, older adults, children, pregnant people, or people with unusual muscle or fluid distribution.
Should I make medical decisions from this?
No. Use BMI as a general estimate and talk with a qualified professional for health decisions.
What units does this calculator use?
This draft uses centimeters for height and kilograms for weight. A future version can add imperial inputs.
What should I check next?
For broader context, compare BMI with BMR, TDEE, ideal weight, and calorie calculators, while keeping medical limitations in mind.