The formula
saving = cigarettes a day × days × price per cigarette
Where it comes from
The money part is a multiplication, but seeing it written down changes the perception: tobacco is paid for in small amounts many times over, which is the way a cost is hardest to notice. The health milestones are another matter: they are measured and published by public health bodies, and the early ones arrive sooner than people expect. Pulse and blood pressure return to normal in twenty minutes, and carbon monoxide clears from the blood in twelve hours.
How to work it out by hand
- Divide the price of the pack by the cigarettes it holds: that is the unit price
- Multiply by the cigarettes you used to smoke a day
- Multiply by the days since you quit
- For minutes of life, count eleven per cigarette not smoked
What is worth knowing
The eleven minutes per cigarette come from a calculation published in the BMJ in 2000: the years of life lost to smoking, divided by the cigarettes smoked over a lifetime. It is a population average, not a prediction about any one person, and it is worth reading as what it is — an order of magnitude. What is individual and checkable is the money, and the time you get back: five minutes a cigarette is more than fifty hours a month for a pack-a-day smoker.