Health
Body Mass Index Estimate
BMI Calculator
Estimate body mass index using US or metric units and view the common adult BMI category.
What is BMI?
BMI Calculator is a free online tool for free BMI calculator using US or metric units to estimate body mass index and adult BMI category.
It gives the page a clear purpose for visitors and search engines: the calculator is available first, and the explanatory content below helps users understand what the result means.
How to use this bMI Calculator
Enter the values requested by the calculator, review any unit or mode selections, and read the result displayed below the form. You can change the inputs and calculate again as many times as needed.
The tool runs in your browser, so it is useful for quick estimates, study notes, comparisons, and everyday reference without creating an account.
BMI formula
BMI is calculated as weight in kilograms divided by height in meters squared. In US units, the formula is weight in pounds divided by height in inches squared, multiplied by 703.
When a result depends on rates, units, dimensions, or formatting rules, make sure the inputs match the labels shown in the calculator before using the output.
BMI Calculator example
For example, a person who is 175 cm tall and weighs 75 kg has a BMI of about 24.5, which is usually shown in the normal weight range.
Small changes in the input can sometimes create a large change in the answer, so examples are a good way to understand the calculation before using your own values.
Frequently asked questions
Is this bMI Calculator free to use?
Yes. The calculator is free to use in your browser and is designed for quick reference.
Can I use the result as an official value?
The result is a helpful estimate or educational calculation. For financial, tax, legal, medical, or engineering decisions, confirm the result with an official source or qualified professional.
Why does the result change when I adjust one input?
Most calculators use formulas where each input affects the final answer. Changing a rate, unit, dimension, date, or amount changes the calculation immediately.