How Many Attempts Does It Really Take to Quit Smoking? The Truth Behind the 30-Attempt Statistic

The widely repeated claim that it takes 30 attempts to quit smoking comes from a single 2016 study, and the real picture is more nuanced than the headline. That same study produced four different estimates, ranging from about 6 attempts to as many as 142, depending entirely on the assumptions used to calculate them. The honest answer is that there is no fixed number, and the exact figure matters less than what it is really telling you: quitting is usually a process of repeated attempts, and that is normal, not failure.

If you have tried to quit several times and gone back to smoking, you may have taken that as proof you cannot do it. The data says the opposite. Repeated attempts are how most successful quitters got there.

Where the 30 Came From

The number traces to one specific paper: Chaiton and colleagues, published in BMJ Open in 2016. They followed 1,277 smokers in Ontario, Canada, over up to three years, checking in roughly every six months. Crucially, they did not just ask people to remember their past attempts, which is how earlier and lower estimates were produced. They tracked attempts as they happened.

That difference matters. Earlier estimates of around 6 attempts relied on the lifetime recall of people who had successfully quit. That approach has a built-in blind spot, which the Chaiton study was specifically designed to fix.

Why Older Estimates Were Probably Too Low

Think about who gets counted when you only survey successful quitters and ask them to recall. You systematically miss the people who tried many times and had not yet succeeded. The smokers who struggle most, the ones who would push the average up, are exactly the ones excluded from a sample of people who already made it. Memory bias compounds the problem, since few people accurately recall every quit attempt across decades.

The Chaiton study corrected for both. By following a full cohort over time, including those still struggling, it captured the harder-to-quit smokers that recall-based studies left out. That is why its estimates came in higher.

The Four Numbers, Not One

Here is the part the viral version always drops. The study did not produce a single answer. It produced four, because the result depends heavily on the statistical assumptions you make:

•        About 6.1 attempts, using the assumptions consistent with older research.

•        About 19.6 attempts, using a constant-rate approach.

•        About 29.6 attempts, using the method the authors judged to have the lowest bias. This is the source of the rounded “30” figure.

•        As many as 142 attempts, using an approach that included recall of attempts before the study began.

So “30” is not a hard fact. It is the authors' best-estimate figure, the one they considered least biased, pulled out of a range that runs from 6 to 142. Quoting it as the number to quit is a simplification of what the science actually says.

What the Authors Actually Concluded

The researchers were careful about their own takeaway. Their point was not that every smoker needs exactly 30 tries. It was that previous estimates were likely too low because they excluded harder-to-quit smokers, and that understanding quitting may take many attempts can help set realistic clinical expectations. In other words, the value of the finding is not the precise digit. It is the reframing: persistence across multiple attempts is the normal path, not a sign you are uniquely bad at this.

Why This Reframe Matters More Than the Number

The most damaging belief a smoker can hold is that a past failed attempt proves they cannot quit. That belief becomes self-fulfilling. It is the engine behind giving up after a slip, and it is why the all-or-nothing mindset is so dangerous.

The data dismantles it. If the typical path to quitting involves many attempts, then a failed attempt is not evidence against you. It is a normal data point on a normal road. Every attempt also teaches you something about your triggers, which is exactly the information a smarter next attempt can use.

Why Some Attempts Work When Others Do Not

If repeated attempts are normal, the useful question is not how many, but what changes between the ones that fail and the one that finally works. Most failed attempts rely on willpower alone against a habit that is largely psychological and automatic. The desire is still fully intact, so the smoker is white-knuckling against their own mind, and most people lose that fight eventually.

Approaches that address the psychology directly aim to change the odds on each attempt rather than just adding another one to the pile. QuitSure, a structured quit smoking program, uses cognitive behavioural therapy, rational emotive behaviour therapy, and guided self-hypnosis to dismantle the beliefs and triggers behind the habit, so quitting depends less on raw willpower. It has people keep smoking until the last day, taking apart the psychology of the habit before the behaviour changes.

In its 2024 JMIR Human Factors study, 80.1% of 1,286 program completers reported staying smoke-free for at least 30 days. Read with the appropriate caution: that is a self-reported survey of people who finished the program, a motivated and self-selected group, not a randomised trial, so it speaks to the promise of the approach rather than proving cause. If you want to understand why early attempts so often unravel, our piece on when most smokers relapse looks at the timing.

The Bottom Line

It does not reliably take 30 attempts to quit smoking. That figure is one of four estimates from a single study, ranging from 6 to 142, and the precise number was never the point. What the research actually shows is that quitting is usually a process of repeated tries, that this is completely normal, and that a past failure is not a verdict on your future. The next attempt is the one that counts.

References

1.     Chaiton M, Diemert L, Cohen JE, Bondy SJ, Selby P, Philipneri A, Schwartz R. Estimating the number of quit attempts it takes to quit smoking successfully in a longitudinal cohort of smokers. BMJ Open. 2016;6(6):e011045. https://pubmed.ncbi.nlm.nih.gov/27288378/

2.     Chaiton M, et al. (estimates of 6.1, 19.6, 29.6, and 142 attempts under differing assumptions; full text). https://www.researchgate.net/publication/303906528_Estimating_the_number_of_quit_attempts_it_takes_to_quit_smoking_successfully_in_a_longitudinal_cohort_of_smokers

Goldgof GM, Mishra S, Bajaj K. Efficacy of the QuitSure App for Smoking Cessation in Adult Smokers: Cross-Sectional Web Survey. JMIR Hum Factors. 2024;11:e49519. https://humanfactors.jmir.org/2024/1/e49519/