# Parts Per Converter

## conversion from PPM to units such as percent or parts per billion (PPB)

### How to calculate PPM and percents

All of the proportion metrics are quite similar: they describe small values of dimensionless quantities, such as the volumetric proportion of $NO_{2}$ in the air. For example, PPM means "parts per million". If you find out that the concentration of $NO_{2}$ is equal to 1 ppm, it means that if you take a "sample" of air and divide it into a million parts, one of them will consist of $NO_{2}$.

The proportion metrics are as follows:

**Percentage**: equal to 1 per 100;**Permille**: equal to 1 per 1,000;**PPM**: equal to 1 per 1,000,000;**PPB**: equal to 1 per 1,000,000,000; and**PPT**: equal to 1 per 1,000,000,000,000.