Smoking and Life Expectancy
Smoking for life takes about 10 years off life expectancy. The good news: quitting at 30 wins back almost all of it, quitting at 40 about 9 years, at 50 about 6 and at 60 about 3. These figures come from a 50-year study of British doctors. Try it with your own details in the calculator below.
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Smoking and life expectancy: how many years does smoking take?
The clearest answer comes from Richard Doll and Richard Peto’s study of more than 34,000 male British doctors, followed for 50 years from 1951. Men born in the early 20th century who smoked all their lives died about 10 years sooner, on average, than men who never smoked. At least half of those who kept smoking were eventually killed by it.
In our model, a 35-year-old UK man who smokes for life loses about 10 years compared with a non-smoker, which matches the study closely.
How many years do you gain by quitting?
| Quit at age | Estimate if you keep smoking | Estimate if you quit | Years gained |
|---|---|---|---|
| 30 | 70.3 | 80.4 | +10.1 |
| 40 | 71.1 | 80.3 | +9.3 |
| 50 | 72.4 | 78.2 | +5.8 |
| 60 | 74.9 | 77.8 | +2.9 |
| 70 | 78.8 | 79.7 | +0.8 |
The earlier the better, but it is never pointless. Even at 60, stopping is worth about 3 years. Risk of a heart attack starts to fall within the first year after quitting, and lung damage slows.
Is smoking a few cigarettes a day safe?
No level of smoking is safe. Even light smoking raises the risk of heart disease and stroke. Cutting down helps less than quitting fully. Our calculator uses years smoked as a simple measure of exposure. If you smoke lightly, choose the shorter band.
What about vaping or other tobacco?
The calculator doesn’t include vaping, cigars, pipes or chewing tobacco, because there is no long-term study that gives a clear years figure for them yet. Cigars, pipes and chewing tobacco carry their own serious risks, such as mouth and throat cancer. If you only vape, answer “never smoked” and read your result with that in mind.
Where to get help quitting
Of all the links between habits and lifespan, smoking and life expectancy is the clearest, and the easiest to change for the better.
Free stop-smoking services make quitting much more likely than going it alone. The NHS says its local services can make you up to three times more likely to quit. In the US, call 1-800-QUIT-NOW. In the UK, search “NHS Quit Smoking”. Elsewhere, ask your doctor or pharmacist about local support and nicotine replacement.
Why the British doctors study is the key source on smoking and life expectancy
Many studies look at smoking and life expectancy. The study by Richard Doll and Richard Peto stands out for three reasons. It started in 1951 and ran for 50 years. It followed more than 34,000 men, so the numbers are large. And the men were doctors, who kept good records and were easy to trace.
Because it lasted so long, it could compare people who smoked all their lives with people who never smoked, and with people who stopped at different ages. That is exactly what you need to measure smoking and life expectancy in years rather than as a vague risk.
As a guide to smoking and life expectancy today, it has limits too. Everyone in it was a man, a doctor and British, and they were born early in the 20th century. Cigarettes, medicine and daily life have changed since then. So we treat its figures as the best long-run guide, not as an exact forecast for anyone today.
Why quitting earlier wins back more years
Smoking and life expectancy are linked through time. The damage from smoking builds up year by year. The longer someone smokes, the more of it there is. When a person stops, much of the extra risk fades, and the body has more time to benefit the younger they are.
That is why the link between smoking and life expectancy depends so much on the age you stop. In the study, men who quit around 30 had almost the same life expectancy as men who never smoked. Quitting at 40 won back about 9 years, at 50 about 6 and at 60 about 3.
Our calculator copies this pattern. It keeps a share of the smoking effect after you quit, and that share grows with your age at quitting:
| Quit at age | Share of the smoking effect that remains |
|---|---|
| 30 or younger | 0% |
| 40 | 5% |
| 50 | 36% |
| 60 | 62% |
| 70 | 85% |
So a person who quit at 50 carries about a third of the extra risk into later life, and leaves about two thirds behind. With these settings, our model gives back 10.0, 9.5, 6.4 and 3.6 years for quitting at 30, 40, 50 and 60, within about 0.6 years of the study.
Is it ever too late to quit?
The study stopped at age 60 for its “years won back” figures, but the gain did not suddenly vanish there. In our model, a UK man who has smoked for 30 years or more and quits at 70 still gains about 0.8 years compared with carrying on.
Less than a year may sound small when you think about smoking and life expectancy. But the benefits of stopping are not only about the length of life. Breathing, energy, taste and smell often improve, and the risk of a heart attack starts to fall within the first year. Those gains matter at any age.
So on smoking and life expectancy, the message is simple. Stopping earlier is better, stopping later still helps, and there is no age where it becomes pointless.
How the calculator turns smoking and life expectancy into years
For smoking, the death clock calculator uses “effective age”. That is the number of years your risk behaves as if you were older. A person who has smoked for 30 years or more is treated as if their risk were about 10.6 years older at every age.
| Years smoked | Risk behaves as if older by |
|---|---|
| Under 10 | 4 years |
| 10 to 19 | 6.5 years |
| 20 to 29 | 8.5 years |
| 30 or more | 10.6 years |
This is how we bring smoking and life expectancy together in one number. Effective age is not the same as years lost, but for lifelong smoking the two end up close, at about 10 years. The survival curve for your country and sex then turns that higher risk into an estimate. The full method is on how we calculate.
How to answer the smoking question
- You smoke now: choose “I smoke now” and pick the band for how many years you have smoked in total.
- You used to smoke: choose “I used to smoke and quit” and enter the age you stopped. If you quit and started again a few times, use the age you last stopped.
- You never smoked, or only tried a few: choose “I have never smoked”.
- You only vape: choose “I have never smoked” for now, as the calculator has no long-term figure for vaping.
Smoking and life expectancy for women
The British doctors study followed men only. That is a real gap in what we know about smoking and life expectancy. The same kinds of harm from tobacco, such as heart disease, stroke and lung disease, affect women too, and no level of smoking is safe for anyone.
Our calculator applies the same effective age to women and men. Because women have a lower baseline risk in almost every country, the result in years can come out a little different. Read the figure for women as a reasonable guide to smoking and life expectancy rather than a measured number.
What changes after you stop smoking?
You don’t have to wait decades to see benefits. Smoking and life expectancy is a long-run story, but your body starts to recover much sooner. The changes start early and keep building.
- The first days and weeks. Circulation and breathing begin to improve. Many people notice more energy and a better sense of taste and smell.
- The first year. The risk of a heart attack begins to fall.
- The following years. The risk of stroke and several cancers keeps falling.
- The long run. Quit early enough, and life expectancy comes close to that of people who never smoked.
This is why the link between smoking and life expectancy is often called the most hopeful one in health. Unlike age or genes, it is something you can change, and the body responds.
Practical steps that make quitting easier
Most people need more than one try to stop for good. That is normal, and each attempt teaches you something. These steps help many people:
- Get support. Free stop-smoking services make quitting much more likely than going it alone.
- Ask about nicotine replacement or medicines. A doctor or pharmacist can help you choose what suits you.
- Pick a quit date. Choose a day soon, and tell friends or family so they can help.
- Know your triggers. Coffee, stress, alcohol or certain places can bring on cravings. Plan what you will do instead.
- Treat a slip as a slip. One cigarette doesn’t undo your progress. Start again straight away.
Cutting down can be a step on the way, but full quitting is where the big gains in smoking and life expectancy come from.
Smoking and life expectancy compared with other habits
Of all the habits in our calculator, smoking has the largest single effect. Seeing smoking and life expectancy next to other factors helps put it in context. Here is how it compares with some other figures on this site.
| Factor | Effect on life expectancy, about |
|---|---|
| Smoking for life | 10 years lost |
| BMI of 40 or more | 9.6 years lost |
| BMI of 30 to 34.9 | 3.6 years lost |
| Most active group compared with inactive | 4.5 years gained |
These come from different studies and groups, so they don’t simply add up. Still, they show why stopping smoking is usually the first step people are advised to take. For the other habits, see how to live longer.
What about second-hand smoke?
Breathing in other people’s smoke is harmful too, for adults and especially for children. Our calculator doesn’t ask about it, because the study behind our smoking and life expectancy figures only measured people’s own smoking. If you live with a smoker, a smoke-free home and car protect everyone in it. If you smoke, stepping outside and away from doors and windows is a kind first step while you work on quitting.
A kind word if you smoke
Nicotine is very addictive, and most smokers started young. Needing help to stop is not a weakness. The numbers on this page are not meant to scare anyone. They are meant to show that stopping works, at any age.
If reading about smoking and life expectancy leaves you worried about your own future, that is understandable. Our death anxiety help page has calm, practical steps. And remember that any result from our calculator is an average for a group, with a wide range, not a prediction about you.
Frequently asked questions
How many years does smoking take off your life?
About 10 years on average for lifelong smokers, according to the 50-year study of British doctors by Doll and Peto (BMJ, 2004).
Is it worth quitting smoking at 60?
Yes. In the same study, men who quit at 60 gained about 3 years of life expectancy compared with those who kept smoking. Quitting at 50 gained about 6 years, at 40 about 9, and at 30 about 10.
How fast does your body recover after quitting?
Some benefits start within days and weeks, such as better circulation and breathing. Heart attack risk begins to fall in the first year, and risks of stroke and several cancers keep falling over the following years.
Does the death clock include vaping?
No. There is not yet a long-term study that gives a clear years figure for vaping. If you only vape, choose “never smoked” and keep in mind that the long-term effects are still being studied.
Why is the British doctors study used for smoking and life expectancy?
It followed more than 34,000 male British doctors for 50 years from 1951, so it could compare lifelong smokers, never-smokers and people who quit at different ages. Few studies on smoking and life expectancy are that long or that large. Its main limit is that it only included men.
Does quitting at 70 still help?
Yes. In our model, a UK man who has smoked for 30 years or more and quits at 70 gains about 0.8 years compared with carrying on. Breathing and energy often improve too. You can try your own age at quitting in the death clock calculator.
Does the calculator treat women smokers differently?
It uses the same effective age for women and men, because the key study of smoking and life expectancy followed men only. Women start from a lower baseline risk in almost every country, so the result in years can differ a little. Read it as a guide, not a measured figure.
How should former smokers fill in the death clock?
Choose “I used to smoke and quit” and enter the age you stopped. The model keeps a share of the smoking effect that grows with the age you quit: none if you stopped by 30, about 36% at 50 and 62% at 60. See how we calculate for details.
Is cutting down as good as quitting?
No. Cutting down can be a useful step, but no level of smoking is safe, and even light smoking raises the risk of heart disease and stroke. The large gains in smoking and life expectancy come from stopping completely. A stop-smoking service or a pharmacist can help you plan it.
Source
Doll R, Peto R, Boreham J, Sutherland I. Mortality in relation to smoking: 50 years’ observations on male British doctors. BMJ, 2004; 328: 1519. doi.org/10.1136/bmj.38142.554479.AE
See how smoking compares with other factors on the death clock, or read about BMI and life expectancy.
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