Particulate Concentration Calculator
Convert between particulate matter mass concentration and particle count, and estimate the Air Quality Index (AQI) breakpoint.
Estimated AQI
35
Estimated AQI vs PM2.5 Concentration
Formula
## Particulate Matter and Air Quality PM2.5 refers to fine particles smaller than 2.5 micrometers. These penetrate deep into the lungs and are the most health-relevant air pollutant. ### AQI Estimation **AQI = PM2.5 (ug/m³) x 500 / 500.4** This is a simplified linear approximation. The actual EPA AQI uses piecewise breakpoints. Generally, 0-12 ug/m³ is Good (AQI 0-50), 12-35.4 is Moderate (51-100), and above 55.4 is Unhealthy (151-200).
Esempio Risolto
The local air quality monitor reads 35 ug/m³ PM2.5.
- 01Simplified AQI = 35 x 500 / 500.4 = 35 (approximately)
- 02Linear low-range AQI = 35 x 50 / 12 = 146
- 03In mg/m³ = 35 / 1000 = 0.035 mg/m³
- 04This falls in the Unhealthy for Sensitive Groups range
Domande Frequenti
What is PM2.5?
PM2.5 stands for particulate matter with a diameter of 2.5 micrometers or less. Sources include vehicle exhaust, industrial emissions, wildfires, and cooking.
What PM2.5 level is safe?
The WHO guideline is an annual mean below 5 ug/m³ and a 24-hour mean below 15 ug/m³. The US EPA standard is an annual mean of 9 ug/m³.
How does PM2.5 affect health?
Long-term exposure increases risks of heart disease, stroke, lung cancer, and respiratory illness. Even short-term spikes can trigger asthma and other acute effects.