AQI Calculator

Turn concentrations into sub-AQIs; overall AQI is the dominant (maximum) pollutant.

Last Updated: 31 Jan 2026

US EPA-style sub-indices from concentration breakpoints; overall AQI is the maximum of included pollutants. Not a substitute for regulatory monitors or AirNow averaging rules.

Overall AQI: 84 Moderate

Dominant (max): PM2.5 (24h)

PollutantConc.Sub-AQI
PM2.5 (24h)28 µg/m³84
PM10 (24h)45 µg/m³42
NO₂ (1h)38 ppb36
O₃ (8h)55 ppb51

AQI Calculator (PM2.5, PM10, NO₂, O₃) helps you turn concentrations into sub-aqis; overall aqi is the dominant (maximum) pollutant. It is commonly used by engineers, lab users, field operators for aqi calculator, pm2.5 aqi, air quality index.

What it does

Uses EPA-style breakpoint tables (piecewise linear) for:

  • PM2.5 (24-hour average, µg/m³)
  • PM10 (24-hour average, µg/m³)
  • NO₂ (1-hour average, ppb)
  • O₃ (8-hour average, ppb)

Overall AQI is the maximum of whichever pollutants you include. This does not replicate AirNow NowCast, official QA, or local rounding rules.

City presets are static, illustrative mixes for demos—not live air quality.

Frequently Asked Questions