Retirement planning basics: how to pay a stranger called your future self

Retirement planning is the practice of paying a stranger. The person who will live on your savings shares your name and your bank details but little else: a different body, different needs, perhaps a different city, and no way to send money back in time to ask for more. Retirement planning basics come down to a handful of decisions that move part of today’s income to that future self: how much you will need, where the money goes, how early it starts, and how little of it leaks away in costs along the way.

The question matters more than it used to. People in most wealthy countries now spend far longer in retirement than their grandparents did, and the job of funding those years has drifted from employers and governments toward individuals. A worker whose parents could count on a company pension is now more often handed an investment account and a menu of funds. What happens inside that account is, for many households, a bigger financial decision than buying a home, and it is made in small, almost invisible steps, one payslip at a time.

Most systems build retirement income in layers. A World Bank report from the mid-1990s, Averting the Old Age Crisis, popularised the idea of three pillars. The first is the public pension, such as Social Security in the United States or the state pension in Britain, usually financed by the payroll contributions of people still working. The second is the workplace scheme. It used to be dominated by defined-benefit plans, which promise a set income based on salary and years of service, and is now increasingly made up of defined-contribution plans such as the American 401(k), British auto-enrolment pots or Australian superannuation, where the outcome depends on what goes in and how it grows. The third pillar is personal saving: individual retirement accounts, private pension plans and ordinary investments.

Planning starts with a target. Advisers typically talk about a replacement rate, the share of your working income you will need once the salary stops, and a common rule of thumb puts it around 70 to 80 percent, because commuting, payroll taxes and saving itself disappear in retirement. How much of that the first two pillars cover depends heavily on geography. The OECD’s Pensions at a Glance 2025 estimates that mandatory schemes will replace about 63 percent of net wages for an average earner with a full career, but the range runs from under 35 percent in Ireland and Lithuania to 85 percent or more in Austria, Greece, Luxembourg, the Netherlands, Portugal, Spain and Türkiye. The gap between that figure and your target is what personal saving has to fill.

Time is the strongest tool, because returns earn their own returns. Costs are the quietest enemy. Someone who puts away $500 a month for 40 years at an average annual return of 6 percent would end up with roughly $996,000, from contributions of $240,000. Shave one percentage point off that return, which is roughly what a 1 percent annual management fee does, and the pot shrinks to about $763,000. Identical effort, nearly a quarter less money. These are illustrations rather than promises, since markets guarantee nothing, but the shape of the curve holds at any realistic rate.

Employer contributions are the closest thing to free money in personal finance. A common American formula matches 50 cents for every dollar an employee saves, up to 6 percent of salary, so a worker earning $50,000 who does not join leaves $1,500 a year on the table. Tax rules add a second push. For 2026 the IRS lets Americans put up to $24,500 into a 401(k), plus an extra $8,000 for those aged 50 and over and $11,250 for those aged 60 to 63, and up to $7,500 into an IRA, with a further $1,100 for savers over 50.

The most powerful lever turned out to be psychological rather than financial. In a study published in the Quarterly Journal of Economics in 2001, Brigitte Madrian and Dennis Shea showed what happened when a large US company switched its 401(k) from opt-in to automatic enrolment: participation jumped, with the largest gains among young and lower-paid employees, and a large share of new savers simply kept whatever contribution rate and fund the company had chosen for them. Richard Thaler and Shlomo Benartzi then designed Save More Tomorrow, which asks workers to commit part of future pay rises to their pension; participants went from saving 3.5 percent of income to 13.6 percent by their fourth raise. Governments copied the idea. Britain began rolling out automatic enrolment in 2012 and now requires a minimum of 8 percent of qualifying earnings, at least 3 percent of it from the employer. The SECURE 2.0 Act requires most new US 401(k) plans to enrol workers automatically, and Australia’s compulsory superannuation guarantee reached 12 percent of ordinary earnings in July 2025.

What the money is invested in shifts with age. Younger savers can usually hold more shares, which are volatile but grow faster over decades, while people near retirement tend to move toward bonds and cash. Target-date funds automate that glide path. The danger they guard against is sequence risk: a market crash in the year you stop working does far more damage than the same crash 30 years earlier, because you are selling assets to live on just as prices fall.

Then comes the drawdown, the least discussed and often the hardest stage. The best-known guide is the 4 percent rule, proposed by the financial planner William Bengen in 1994: withdraw 4 percent of your savings in the first year, raise the amount with inflation afterwards, and in historical US market data the money lasted at least 30 years. On a $500,000 pot that means $20,000 in year one. In his 2025 book A Richer Retirement, Bengen raised his figure to 4.7 percent, or $23,500, while still describing it as a worst-case planning number. Public pensions add a timing decision of their own. In the US, anyone born in 1960 or later reaches full Social Security retirement age at 67; claiming at 62 cuts the monthly benefit by 30 percent for life, while waiting until 70 adds 8 percent for each year of delay. Inflation keeps working throughout: at 3 percent a year, prices roughly double in 23 years, which is about the length of a retirement.

None of this needs a spreadsheet to begin. It is the premise of Stephanie Soechtig’s Netflix documentary Get Smart with Money, which follows money coaches advising ordinary people on saving and investing: most good financial outcomes come from a few decisions made early and then left alone. Join the workplace plan, take the full match, raise the rate with every pay rise, keep fees low and choose a fund mix you can live with through a bad year.

The stranger at 70 cannot negotiate, cannot lobby and cannot ask for a raise. The only voice they have is the contribution rate you set this month and then forget to lower.

Tags: personal finance, retirement planning, 4 percent rule, 401(k), automatic enrolment, pensions