I was extremely disappointed with the results returned when I typed the question above into Google – so I thought I’d do the calculations myself.

*NB – I’ve limited my definition of work to mean ‘paid employment’! *

If you work for the entirety of your adult life until pensionable age in the UK then you will be engaged in some form of paid employment from the age of 18 years to of age to 68 years of age, which is an equivalent of 50 years of paid-employment.

If we take the average amount of hours worked per week, which was 39.2 hours in 2014 according to the annual survey of hours and earnings, then you will work a total of 92 120 hours in the course of your working life (based on a rough calculation of 39.2 hours *(52-5 = 47 weeks to take account of holidays)*50 years).

Expressed as terms of a percentage of your life, this 39.2 hours a week spent working is equivalent to

14% of your total times over the course of a 76 year period (based on the average projected life expectancy of 76 for people born in the year 2000 according to the ONS’s National Life Tables for the United Kingdom.)

23.3% of your total time during the course of a 50 year working-life period

21% of your total waking hours over a 76 year lifespan, assuming 8 hours of sleep a night.

35% of your total waking hours over a 50 year working-life period assuming 8 hours of sleep a night

50% of your total waking hours during any given working day.

Of course the above amount of time actually spent working will vary depending on a variety of factors, not least on your income and expenditure, but also on the generosity of your parents, any inheritance you might receive, returns on investments, and any time you spend on benefits, but the most crucial variable (or combination of variables) which determines how many hours you are going to work over the course of your life is, for most people, **the amount of income you earn ****in relation to**** your expenditure. **

In short, the less you spend in relation to your income, then the less income you need, and the fewer hours, days, weeks, months and years (whichever is the least painful way of counting it!) you will need to work.

The maths behind this (thanks to Jacob Lund Fisker) is actually surprisingly simple – If you take home £20 000 a year, spend £18 000 and save £2000, then it will take you 9 years to save up enough to live for a year (£2000 *9 = £18000).

If you can inverse this ratio, and save £18 000 a year and get used to living off only £2000 then if you work for one year you will have saved enough to live for another 9 years.

If you look at this over the course of a working life, if you can keep the first scenario up (saving £2000/ year) then over 45 years you would save enough to live off for five years, meaning you could retire 5 years earlier, at 62 years of age. In the second example, you could work for 5 years and then retire on your savings at the age of 23, albeit on a lower income.

The first ‘hypothetical’ example is pretty close to the norm in the UK today. In 2012-13 the average personal annual income after tax for the 50%th percentile income-earner was £18 700, while the average annual expenditure for the middle quintile of single person households in 2013 was £16016, leaving a potential savings capacity of approximately £2700 a year for those of middling income and expenditure. (based on the ONS survey of personal income and Equivalised income.)

The second example above is, for most of us, going to remain hypothetical because it is just too extreme. However, consider the half way situation – If, on an average annual take-home salary of £20 000 you can learn to live off £10 000 a year and save £10 000 – you could potentially only work for 25 years…. meaning you could retire at age 43.

If you like this sort of thing – then you might like to buy my book, which is focused on early retirement in the UK

Early Retirement Strategies for the Average Income Earner, or A Critique of the Curiously Ordinary Life of the Everyday Worker-Consumer

Available on iTunes, Kobo, and Barnes and Noble – Only £0.63 ($0.99)

Also available on Amazon, but for £1.99 because I’d get a much lower cut if I charged less!

**Related Posts **

15 Seriously disturbing facts about your job (in which they cite 90 000 hours, which is similar to the figure I got)

Not sure you’ve taken sleep out. As you refer to waking hours, sleep calculation is vital. Assume 7 hours per night.That’s 204400 hours. Meaning there are 262800 waking hours of which 86480 hours are working, which is one third of our hours in our lives are spent working. We spend 57% of our waking time at work during a working life of 46 years.