Air Pollution Index Calculator
Our environmental chemistry calculator computes air pollution index accurately. Enter measurements for results with formulas and error analysis.
Formula
AQI = max(I_PM2.5, I_PM10, I_NO2, I_SO2, I_CO)
The AQI is determined by calculating sub-indices for each pollutant using piecewise linear interpolation between EPA concentration breakpoints, then taking the maximum sub-index as the overall AQI value.
Worked Examples
Example 1: Moderate Air Quality Day
Problem: PM2.5 = 20 ug/m3, PM10 = 80 ug/m3, NO2 = 40 ppb, SO2 = 20 ppb, CO = 3 ppm
Solution: Sub-index PM2.5: I = 51 + ((20 - 12.1)/(35.4 - 12.1)) * (100 - 51) = 67.7\nSub-index PM10: I = 51 + ((80 - 55)/(154 - 55)) * (100 - 51) = 63.4\nSub-index NO2: 37.7, Sub-index SO2: 28.6, Sub-index CO: 34.1\nAQI = max(67.7, 63.4, 37.7, 28.6, 34.1) = 67.7
Result: AQI = 68 (Moderate)
Example 2: Unhealthy Air Quality
Problem: PM2.5 = 80 ug/m3, PM10 = 200 ug/m3, NO2 = 120 ppb, SO2 = 100 ppb, CO = 10 ppm
Solution: Sub-index PM2.5: 163.7, Sub-index PM10: 124.7\nSub-index NO2: 102.0, Sub-index SO2: 112.3\nSub-index CO: 108.6\nAQI = max(163.7, 124.7, 102.0, 112.3, 108.6) = 163.7
Result: AQI = 164 (Unhealthy)
Frequently Asked Questions
What is the Air Quality Index (AQI)?
The Air Quality Index is a standardized numerical scale used by government agencies worldwide to communicate the level of air pollution to the public. The AQI ranges from 0 to 500, where values below 50 indicate good air quality and values above 300 represent hazardous conditions. It is calculated by measuring concentrations of major pollutants including PM2.5, PM10, nitrogen dioxide, sulfur dioxide, and carbon monoxide, then converting each to a sub-index using EPA breakpoint tables.
Can I use Air Pollution Index Calculator on a mobile device?
Yes. All calculators on NovaCalculator are fully responsive and work on smartphones, tablets, and desktops. The layout adapts automatically to your screen size.
How do I interpret the result?
Results are displayed with a label and unit to help you understand the output. Many calculators include a short explanation or classification below the result (for example, a BMI category or risk level). Refer to the worked examples section on this page for real-world context.
How do I get the most accurate result?
Enter values as precisely as possible using the correct units for each field. Check that you have selected the right unit (e.g. kilograms vs pounds, meters vs feet) before calculating. Rounding inputs early can reduce output precision.
Can I share or bookmark my calculation?
You can bookmark the calculator page in your browser. Many calculators also display a shareable result summary you can copy. The page URL stays the same so returning to it will bring you back to the same tool.
How accurate are the results from Air Pollution Index Calculator?
All calculations use established mathematical formulas and are performed with high-precision arithmetic. Results are accurate to the precision shown. For critical decisions in finance, medicine, or engineering, always verify results with a qualified professional.