Measured indoor PM2.5
What Is the AQI of Cigarette Smoke?
A cigarette does not have one fixed AQI. AQI represents an ambient pollutant concentration over a defined averaging period, so the result changes with room size, ventilation, distance from the source, and when you sample. Enter before-and-after PM2.5 readings to place your room measurement on the US PM2.5 AQI scale.
Compare your room before and after smoke
Use PM2.5 readings from the same sensor and location. This estimates a US PM2.5 AQI level from measured concentration; it does not infer the number of cigarettes or an inhaled dose.
Room measurement result
Baseline US PM2.5 AQI equivalent
AQI 44
8 µg/m³ · Good
Measured US PM2.5 AQI equivalent
AQI 225
150 µg/m³ · Very Unhealthy
Increase above baseline
+142 µg/m³
Excess particle-hours
142 µg·h/m³
Move to cleaner air while the room clears
- Stop the source, run high-smoke-CADR filtration, and ventilate only if outdoor air is cleaner.
- Avoid staying in the affected room until repeated readings show a sustained decline.
Particle-hours are concentration above baseline multiplied by the entered time. This ambient measurement is not an inhaled dose, a medical diagnosis, or a way to calculate how many cigarettes were smoked.
How the cigarette smoke AQI calculation works
- Use baseline and smoke readings from the same PM2.5 sensor and location. A direct smoke plume can overwhelm a consumer sensor and may not represent the whole room.
- Each PM2.5 reading is truncated to one decimal and converted to an AQI equivalent with the current US EPA PM2.5 breakpoints.
- The concentration increase subtracts the before-smoking baseline. Particle-hours multiply that increase by the time you enter.
- AQI 500 is the end of the standard reporting scale. Higher concentrations are labeled >500 rather than presented as a precise standard AQI.
Air quality tools for the decision in front of you
Start with the number or question you already have. Every tool leads to a concrete calculation, comparison, or action plan instead of another generic article.
Daily air pollution exposure planner
Combine the places in your day into a time-weighted PM2.5 comparison.
Lifetime air pollution exposure timeline
Weight annual PM2.5 by the years spent in each place you lived.
Air purifier size calculator
Calculate smoke CADR, air changes per hour, and purifier count for a room.
Trust Signals
What a room PM2.5 measurement can—and cannot—tell you
Review policy
August 8, 2026. We update supporting pages when calculator logic, live data behavior, or source framing changes.
Primary sources
AQI uses EPA / AirNow breakpoint logic. Cigarette-equivalent framing follows Berkeley Earth’s PM2.5 interpretation.
Live data layer
City pages use EPA AirNow where supported, with cached fallbacks and planning baselines if the API fails or coverage is unavailable.
Cigarette smoke AQI questions
What is the AQI of one cigarette?
There is no fixed AQI for one cigarette. AQI describes an ambient pollutant concentration, not a source count. Room volume, ventilation, sensor position, smoke dispersion, and sampling time can produce very different readings from the same cigarette.
Can I estimate cigarette smoke AQI from cigarette count?
Not reliably. This calculator deliberately requires measured PM2.5 before and after smoke instead of estimating a room AQI from cigarette count or room volume.
Should I enter a peak or an average PM2.5 reading?
Use an average over the exposure period when possible. A peak shows the highest momentary concentration; multiplying a peak by time is only an upper-bound scenario that assumes the peak persisted.
What does a cigarette smoke AQI above 500 mean?
The standard US AQI reporting scale ends at 500. A PM2.5 concentration above that boundary is still a severe measured smoke condition, but any higher numeric AQI would be an extrapolation rather than a standard reported value.