What is the difference between the China AQI and US AQI? The technical answer is that both systems use the same formula. The difference, however, is in the AQI thresholds. You will see that for an AQI above 200 (151 μg/m3 PM2.5 concentration), the US and Chinese AQI systems report the same numbers for the same concentrations.

To learn more about the Chinese and US AQI systems, click the following link: