Parts Per Converter

All of the proportion metrics are quite similar: they describe small values of dimensionless quantities, such as the volumetric proportion of NO2NO2​ in the air. For example, PPM means "parts per million". If you find out that the concentration of NO2NO2​ 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 NO2NO2​.

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.