Guide
What changes your figures
The calculator uses population averages, adjusted for the area you live in if you add a postcode. Your own circumstances can move your figures a long way from those averages. These are the biggest factors.
Smoking
Smoking has the largest effect of any single habit. The 50-year British Doctors Study found that people who smoked throughout their lives died about 10 years earlier on average than people who never smoked, and that about half of continuing smokers were eventually killed by smoking.
Stopping helps at any age. Compared with carrying on, stopping gained about:
| Age at stopping | Life expectancy gained |
|---|---|
| 30 | Almost all of the 10 years |
| 40 | About 9 years |
| 50 | About 6 years |
| 60 | About 3 years |
A 2024 analysis by University College London, using the British Doctors Study and the Million Women Study, put the cost at about 17 minutes of life per cigarette for men and 22 minutes for women.
The ONS figures used in the calculator include smokers in proportion to how many people smoke, so they sit between what a smoker and a non-smoker could expect. There is no official UK table to adjust for smoking, so the calculator doesn't try. If you smoke, treat your figures as optimistic. If you have never smoked, they are likely to be cautious.
Health conditions
Serious conditions such as heart disease, cancer, diabetes and lung disease can shorten life expectancy considerably, depending on how severe and well managed they are. Being very overweight, drinking heavily and being inactive also reduce it. If any of these apply, your figures are likely to be on the high side.
Family history
Long-lived parents and grandparents are linked to longer lives, partly through genes and partly through shared habits and circumstances. The effect is real but modest compared with smoking or serious illness.
Wealth and education
People with higher incomes and more education tend to live longer. The postcode adjustment captures some of this through your local area, but not all of it. If you are better off than most people in your area, your figures may be cautious.
If you are using the figures to plan, it is safer to assume you might live longer than average. Running out of money late in life is usually a bigger problem than leaving some unspent.