Work out what the habit costs, either what you're spending now or what you've saved since you stopped. I wrote the original of this the week I quit, on the theory that a number on a screen argues better than I do.

What it costs

• A day$9
• A week$63
• A month$274
• A year$3,287
• Five years$16,436

What it has cost already

At 20 a day for 10 years, that's $32,873 and about 18 months of life expectancy, at the eleven-minutes-a-cigarette figure the leaflets use.

If you stop

1. 20 minutesHeart rate and blood pressure drop back down.$3 saved
2. 12 hoursCarbon monoxide in your blood is back to normal.$9 saved
3. 2 weeksCirculation improves and walking gets easier.$126 saved
4. 1 monthCoughing and shortness of breath start to ease.$270 saved
5. 1 yearRisk of coronary heart disease is half a smoker's.$3,285 saved

The health milestones are the standard cessation timeline, not anything I worked out. I'm a tester, not a doctor.