Power Calculators

😷 AQI Exposure Planner

Calculate U.S. EPA PM2.5 AQI and estimate cumulative AQI-hours for a planned outdoor exposure period. The AQI-hours value is a planning metric, not a medical dose measurement.

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Enter details

Enter the 24-hour PM2.5 concentration used for the EPA AQI calculation.
Enter the number of hours you expect to spend outdoors.
Estimated U.S. EPA PM2.5 AQI
168
PM2.5 Used for AQI (µg/m³)
80
AQI-Hours Planning Metric
168
AQI Category Code
4

Also available in our Android app, with charts and full breakdown tables.

📘 About the AQI Exposure Planner

This calculator uses the U.S. EPA AQI methodology for 24-hour PM2.5.

AQI is an index used to communicate air pollution levels and associated public-health guidance.

The AQI is calculated separately for individual pollutants and the reported AQI is normally the highest pollutant-specific index.

This calculator focuses specifically on PM2.5 because PM2.5 is a major outdoor particulate pollutant and has a clearly defined EPA breakpoint table.

The AQI-hours result is provided only as a planning metric and is not an official measure of inhaled pollution dose.

✏️ Worked examples

Example 1 - PM2.5 of 20 µg/m³

You enter
PM2.5 Concentration20 µg/m³
Planned Outdoor Exposure2 hours
You get
Estimated U.S. EPA PM2.5 AQI71
PM2.5 Used for AQI (µg/m³)20
AQI-Hours Planning Metric142
AQI Category Code2

A 24-hour PM2.5 concentration of 20 µg/m³ falls within the EPA Moderate PM2.5 breakpoint range and produces an AQI in the moderate category.

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Example 2 - PM2.5 of 8 µg/m³

You enter
PM2.5 Concentration8 µg/m³
Planned Outdoor Exposure3 hours
You get
Estimated U.S. EPA PM2.5 AQI44
PM2.5 Used for AQI (µg/m³)8
AQI-Hours Planning Metric132
AQI Category Code1

A PM2.5 concentration of 8 µg/m³ falls in the EPA Good category.

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Example 3 - PM2.5 of 80 µg/m³

You enter
PM2.5 Concentration80 µg/m³
Planned Outdoor Exposure1 hours
You get
Estimated U.S. EPA PM2.5 AQI168
PM2.5 Used for AQI (µg/m³)80
AQI-Hours Planning Metric168
AQI Category Code4

A PM2.5 concentration of 80 µg/m³ falls in the EPA Unhealthy range for the PM2.5 sub-index.

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🧭 How to use this calculator

What you enter

  • PM2.5 Concentration (µg/m³)Enter the 24-hour PM2.5 concentration used for the EPA AQI calculation.
  • Planned Outdoor Exposure (hours)Enter the number of hours you expect to spend outdoors.

What you get

  • Estimated U.S. EPA PM2.5 AQI
  • PM2.5 Used for AQI (µg/m³)
  • AQI-Hours Planning Metric
  • AQI Category Code

💡 EPA AQI interpolation

  • EPA AQI is calculated by identifying the concentration breakpoint containing the pollutant concentration.
  • The concentration is truncated according to EPA reporting rules before the breakpoint calculation.
  • Linear interpolation is then performed between the corresponding AQI breakpoints.
  • The resulting AQI is rounded to the nearest integer.

💡 PM2.5 AQI categories

  • 0 to 50 = Good.
  • 51 to 100 = Moderate.
  • 101 to 150 = Unhealthy for Sensitive Groups.
  • 151 to 200 = Unhealthy.
  • 201 to 300 = Very Unhealthy.
  • 301 to 500 = Hazardous.

💡 AQI-hours

  • AQI-hours is calculated as AQI multiplied by planned exposure hours.
  • It is included as a simple comparison tool for planning outdoor time.
  • It is not an inhaled dose, medical risk score or EPA-defined health metric.
  • Actual exposure depends on ventilation, breathing rate, indoor filtration, activity level and many other factors.

💡 Important jurisdiction note

  • The AQI system used here is the U.S. EPA AQI.
  • Other countries use different AQI scales, pollutant breakpoints and averaging periods.
  • Do not assume this EPA AQI value is identical to the Indian National Air Quality Index.

❓ Frequently asked questions

What AQI standard does this calculator use?

It uses the U.S. EPA AQI methodology for 24-hour PM2.5.

What does AQI mean?

AQI means Air Quality Index, an index used to communicate air pollution conditions and associated health guidance.

What is AQI-hours?

AQI-hours is a simple planning metric calculated by multiplying the AQI by planned outdoor exposure hours. It is not an official EPA medical or dose metric.

Does this calculator calculate Indian AQI?

No. This version explicitly uses the U.S. EPA PM2.5 AQI scale. India uses its own National Air Quality Index framework.

What PM2.5 value is considered Good in the EPA AQI?

For the current EPA PM2.5 breakpoint table, 0.0 to 9.0 µg/m³ corresponds to AQI 0 to 50.

Why is PM2.5 truncated before AQI calculation?

EPA AQI calculation guidance specifies pollutant-specific truncation before selecting the concentration breakpoint.

Is AQI a personal health-risk score?

No. AQI communicates population-level air-quality conditions. Individual response can vary considerably.