What this counts, and what it leaves out
The maths is short. Cigarettes a day, times the price of one cigarette, times days since you quit. The price of one cigarette is the pack price divided by how many come in the pack, which is why both fields are there: a 20-pack and a 25-pack at the same price are not the same habit.
It leaves out lighters, the second coffee that came with the cigarette, and the price rise that will happen at the next budget. It also leaves out every health effect. Many sites show a timeline of what happens to your body at 20 minutes, 12 hours, and so on. We have not put one here, because the figures on those pages are usually quoted without a source, and this page does not repeat numbers it cannot point to.