Smog Calculator

Convert an Air Quality Index into an equivalent number of cigarettes.

Equivalent cigarettes per day 0.2

Formula: 1 cigarette ~22 ug/m3 PM2.5 for a day; AQI to PM2.5

Step-by-step with your numbers:

1. Values used:

2. Air Quality Index (AQI) = 150

3. Hours per day outdoors = 2

5. Equivalent cigarettes per day = 0.2

Did we solve your problem today?

A rough rule equates breathing high-PM2.5 air to the harm of smoking cigarettes.

The math behind it

Roughly, a 22 ug/m^3 daily PM2.5 exposure is comparable to one cigarette. This estimates from AQI.

AQI 150 (PM2.5 ~52 ug/m^3) over 2 hours outdoors is like about 0.2 cigarettes.

Is this medically exact?

No — it is a rough communication tool to make air pollution feel more tangible.