Calculateur d'Indice de Qualité de l'Air — Formule
## How to Calculate Air Quality Index
The AQI converts pollutant concentrations into a standardized scale.
### Simplified PM2.5 to AQI
**AQI (approx) = PM2.5 * 4.167** (for values up to ~100 AQI)
### AQI Categories
- **0-50**: Good (green)
- **51-100**: Moderate (yellow)
- **101-150**: Unhealthy for sensitive groups (orange)
- **151-200**: Unhealthy (red)
- **201-300**: Very unhealthy (purple)
- **301+**: Hazardous (maroon)
The WHO guideline for annual PM2.5 is 5 ug/m3.
The AQI converts pollutant concentrations into a standardized scale.
### Simplified PM2.5 to AQI
**AQI (approx) = PM2.5 * 4.167** (for values up to ~100 AQI)
### AQI Categories
- **0-50**: Good (green)
- **51-100**: Moderate (yellow)
- **101-150**: Unhealthy for sensitive groups (orange)
- **151-200**: Unhealthy (red)
- **201-300**: Very unhealthy (purple)
- **301+**: Hazardous (maroon)
The WHO guideline for annual PM2.5 is 5 ug/m3.
Exemple Résolu
PM2.5 of 35 ug/m3, spending 2 hours outdoors daily for 250 days/year.
- AQI: 35 * 4.167 = 146 (Unhealthy for sensitive groups)
- Annual exposure: 35 * 2 * 250 = 17,500 ug*hr/m3
- vs WHO: 35 / 5 * 100 = 700% above guideline
- Reduction needed: 35 - 5 = 30 ug/m3