Particulate Concentration Calculator

Convert between particulate matter mass concentration and particle count, and estimate the Air Quality Index (AQI) breakpoint.

ug/m³

Estimated AQI

35

AQI (linear approx 0-50 range)146
Concentration in mg/m³0.0350 mg/m³

Estimated AQI vs PM2.5 Concentration

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).

Example Calculation

The local air quality monitor reads 35 ug/m³ PM2.5.

  1. 01Simplified AQI = 35 x 500 / 500.4 = 35 (approximately)
  2. 02Linear low-range AQI = 35 x 50 / 12 = 146
  3. 03In mg/m³ = 35 / 1000 = 0.035 mg/m³
  4. 04This falls in the Unhealthy for Sensitive Groups range

Frequently Asked Questions

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