National Air Quality Index (AQI) Calculator

Enter pollutant concentrations to calculate sub-indices and the overall AQI in real time using CPCB’s 2014 National Air Quality Index methodology.

Use Case

Manual-monitoring field staff can enter measured concentrations.

Public users can understand category, severity, and dominant pollutant.

The bundled spreadsheet remains available for download and reference.

Pollutant	Averaging Period	Unit	Sub-Index
PM2.5	24-hour	µg/m³	—
PM10	24-hour	µg/m³	—
NO₂	24-hour	µg/m³	—
SO₂	24-hour	µg/m³	—
CO	8-hour	mg/m³	—
O₃	8-hour	µg/m³	—
NH₃	24-hour	µg/m³	—
Pb (Lead)	24-hour	µg/m³	—

Overall Result

—

Dominant Pollutant

—

Validity

0 pollutant(s) entered

Insufficient data — enter 3+ pollutants including PM2.5 or PM10.

AQI Legend

Good0–50

Satisfactory51–100

Moderately Polluted101–200

Poor201–300

Very Poor301–400

Severe401–500

Breakpoints reference

Pollutant	0–50	51–100	101–200	201–300	301–400	401–500
PM2.5	0–30	31–60	61–90	91–120	121–250	251–380
PM10	0–50	51–100	101–250	251–350	351–430	431–510
NO₂	0–40	41–80	81–180	181–280	281–400	401–520
SO₂	0–40	41–80	81–380	381–800	801–1600	1601–2620
CO	0–1	1.1–2	2.1–10	10.1–17	17.1–34	34.1–50
O₃	0–50	51–100	101–168	169–208	209–748	749–1000
NH₃	0–200	201–400	401–800	801–1200	1201–1800	1801–2400
Pb (Lead)	0–0.5	0.6–1	1.1–2	2.1–3	3.1–3.5	3.6–4

The calculator uses CPCB’s linear interpolation method: compute a sub-index for each entered pollutant, then report the maximum sub-index as the overall AQI. The dominant pollutant is the one associated with that maximum value.

Excel File

Downloadable Spreadsheet

Method and breakpoints follow CPCB’s National Air Quality Index (2014). This calculator is provided for reference and quick estimation.

Download as Excel Calculation Method

File Included on This Page

AQI-Calculator.xlsx

The spreadsheet file is bundled locally and available for direct download from this page.

Download spreadsheet file