❤️ BMI Calculator
How It Works
Calculate your Body Mass Index (BMI) to assess if your weight is in a healthy range for your height. Use BMI Calculator as a general estimate from the measurements and assumptions you enter.
The result is most useful when the inputs match the definitions used by this calculator. For this tool, the underlying method is: BMI = weight(kg) / height(m)² or BMI = (weight(lbs) / height(in)²) × 703. Compare the output with the worked example, then change one meaningful input at a time to see how the result responds.
What Is BMI?
BMI (Body Mass Index) is a ratio of body weight to height used as a population-level screening measure. It can describe weight relative to height, but it does not directly measure body fat or overall health.
How to interpret the result: Compare the output with the worked example and with another scenario using the same definitions. For this calculator, the key relationship is BMI = weight(kg) / height(m)² or BMI = (weight(lbs) / height(in)²) × 703.
How to Calculate BMI
The page uses the method shown in the Formula section: BMI = weight(kg) / height(m)² or BMI = (weight(lbs) / height(in)²) × 703. Keep the inputs in matching units, then change one meaningful input at a time when testing scenarios.
Important limitation: BMI should not be treated as a diagnosis. Muscle mass, body composition, age, and other health factors can affect how meaningful it is for an individual. Review the bmi inputs and units before relying on the result.
How BMI is calculated
BMI uses weight relative to height squared. The same underlying calculation can be expressed using metric or imperial units.
BMI categories and limitations
BMI categories are population-level screening ranges. BMI does not directly measure body fat, muscle mass, fat distribution, or overall health, so the result should be interpreted in context.
Use BMI as one signal
For individual health decisions, body composition, waist measures, fitness, medical history, age, and other factors may provide useful context beyond a single BMI value.
When to Use This Calculator
Use BMI Calculator as a general estimate from the measurements and assumptions you enter.
Practical tip: For this BMI Calculator, use the result as a starting estimate and change one measurement or activity assumption at a time so you can see how sensitive the estimate is.
Formula
BMI = weight(kg) / height(m)² or BMI = (weight(lbs) / height(in)²) × 703
Example
A person weighing 70 kg and 175 cm tall has a BMI of 70 / (1.75)² = 22.9, which is in the normal weight range. Use the calculator to test a second scenario and see how the result changes when one important assumption is adjusted.