How is the AQI Calculated?
The AQI is calculated every hour for each air quality parameter using the
formulas indicated below. The highest number calculated for a specific hour is
used as the AQI for that hour.
| Parameter Name
| Concentration
| Units
| Formula
|
| Carbon Monoxide |
If <= 13 |
ppm |
AQI = 1.92 x Concentration |
| If > 13 |
ppm |
AQI = (1.47 x Concentration) + 5.88 |
| Ozone |
If <= .05 |
ppm |
AQI = 500 x Concentration |
| If > .05 <= .08 |
ppm |
AQI = (833 x Concentration) - 16.67 |
| If > .08 |
ppm |
AQI = (714 x Concentration) - 7.14 |
| Sulphur Dioxide |
All |
ppm |
AQI = 147.06 x Concentration |
| Nitrogen Dioxide |
If <= 0.21 |
ppm |
AQI = 238.09 x Concentration |
| If > 0.21 |
ppm |
AQI = (156.24 x Concentration) + 17.19 |
| Respirable Particulate Matter (PM2.5) |
If <= 30 |
ug/m3 |
AQI = 0.8333 x Concentration |
| If > 30 |
ug/m3 |
AQI = (0.5 x Concentration) + 10 |
|
