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📘 About the Air Pollution to Cigarettes Calculator
Fine particles (PM2.5) are the most harmful part of air pollution: they go deep into the lungs and the bloodstream. Researchers at Berkeley Earth worked out that breathing 22 µg/m³ of PM2.5 for a day causes about the same harm, in terms of early deaths, as smoking one cigarette.
This calculator converts the AQI to PM2.5 (Indian CPCB or US EPA scale), then weighs the hours you are outdoors and indoors — with your mask and windows or air purifier — to estimate the cigarettes you 'smoke' each day. At an Indian AQI of 400 (PM2.5 about 250 µg/m³), staying outdoors all day is like smoking about 11 cigarettes.
✏️ Worked examples
India AQI 400, 3 hours outdoors, no mask
You get| Cigarettes a day (equivalent) | 10.4 |
| If you stayed outdoors all day | 11.4 cigarettes |
| Over 30 days | 311 cigarettes |
| In a year at this level | 3,785 cigarettes (189.2 packs) |
| PM2.5 outdoors | 250 µg/m³ — very poor |
| PM2.5 you breathe (day average) | 228 µg/m³ |
| Times the WHO daily guideline | 16.7× |
10.4 cigarettes a day; 311 cigarettes over a month.
PM2.5 150 µg/m³, N95 outside, purifier at home
You get| Cigarettes a day (equivalent) | 1.7 |
| If you stayed outdoors all day | 6.8 cigarettes |
| Over 1 day | 1.7 cigarettes |
| In a year at this level | 633 cigarettes (31.6 packs) |
| PM2.5 outdoors | 150 µg/m³ — very poor |
| PM2.5 you breathe (day average) | 38 µg/m³ |
| Times the WHO daily guideline | 10.0× |
1.7 cigarettes a day instead of 6.8 cigarettes outdoors all day.
🧭 How to use this calculator
What you enter
- I know the
- AQI or PM2.5 valueFrom your air-quality app for your city or area. PM2.5 gives the most accurate result.
- Hours outdoors a day (h)Commute, walks, work or play outside.
- Indoors you are
- Mask outdoors
- Days at this level (days)For example 30 for a month of winter smog.
What you get
- Cigarettes a day (equivalent)
- If you stayed outdoors all day
- Over 1 day
- In a year at this level
- PM2.5 outdoors
- PM2.5 you breathe (day average)
- Times the WHO daily guideline
💡 Ways to cut your exposure
- Check the AQI before going out; move exercise indoors or to early afternoon when levels are usually lower in winter.
- A well-fitted N95/FFP2 mask filters most fine particles; cloth and loose surgical masks help far less.
- Keep windows shut on bad days and run a HEPA air purifier sized for the room (CADR at least 2/3 of the room area in sq ft).
- Avoid burning incense, mosquito coils and wood indoors — they add to the PM2.5 you breathe.
- Children, older people, pregnant women and people with asthma or heart disease should be most careful.
❓ Frequently asked questions
How many cigarettes is AQI 300?
On the Indian (CPCB) scale an AQI of 300 means PM2.5 of about 120 µg/m³ — roughly 5.5 cigarettes a day if you are outdoors all day. On the US scale AQI 300 is about 225 µg/m³, or 10 cigarettes.
Is the cigarette comparison exact?
No — it compares the effect on early deaths, not the exact chemicals. Cigarettes also contain nicotine and other toxins, while polluted air harms everyone in a city, including babies. It is a way to understand the size of the risk.
Does an N95 mask really help?
Yes, a well-fitted N95 or FFP2 mask filters most PM2.5. Real-world fit is not perfect, so this calculator assumes it lets in about 30%. Cloth masks let in most fine particles.
What people are saying
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Anonymous · 09 Nov 2026