BMI Calculator
Calculate body mass index with metric or US units, BMI category, healthy weight range, BMI Prime, and Ponderal Index.
Calculator updated
Use this page to get the result quickly, then review the formula, table, chart, or example for context.
- Estimate adult BMI category
- Find healthy weight range for a height
- Compare BMI with BMI Prime and Ponderal Index
- Formula, example, and related calculators
Formula
BMI = weight(kg) / height(m)^2. BMI Prime = BMI / 25. Ponderal Index = weight(kg) / height(m)^3.
Example
A person who weighs 70 kg and is 175 cm tall has a BMI of 22.9, which is in the healthy adult BMI range.
When to Use
- Estimate adult BMI category
- Find healthy weight range for a height
- Compare BMI with BMI Prime and Ponderal Index
Common Mistakes
- Using BMI as a complete health diagnosis
- Applying adult BMI categories to children without growth charts
- Ignoring muscle mass, pregnancy, age, or medical context
Fast Result
The calculator updates from your inputs and keeps the result easy to copy, print, or save locally.
Transparent Formula
The formula and example show how the result is built, so the page is useful beyond a single calculation.
Related Next Steps
Use the related links to move from estimate to comparison, payoff, conversion, or planning.
How this bmi calculator works
Calculate body mass index with metric or US units, BMI category, healthy weight range, BMI Prime, and Ponderal Index.
Enter the values you know, review the primary result, then use the table or chart to understand the details. The result is an estimate and should be checked against professional advice when money, medical, tax, legal, or engineering decisions are involved.
Frequently Asked Questions
Is BMI a diagnosis?
No. BMI is a screening measure, not a diagnosis. It does not directly measure body fat or health status.
Does BMI work for children?
Children and teens should be assessed using age- and sex-specific BMI percentiles from qualified health references.
What is BMI Prime?
BMI Prime compares your BMI with 25, the upper end of the adult healthy BMI range.