Retirement Calculator

Your retirement corpus comes from two engines working together. The first is the lump sum you have already saved, which compounds on its own from today until the day you retire. The second is the stream of monthly contributions you keep adding, each of which compounds for however long it stays invested. The calculator grows both forward to your retirement date and adds them, so you see the combined result.

The expected return is the single most important — and most uncertain — input. A diversified portfolio of stocks and bonds has historically returned somewhere in the mid-to-high single digits per year over long periods, but real returns vary year to year and are never guaranteed. It is worth running the projection at a couple of different return assumptions to see how sensitive your outcome is; the spread between, say, 6% and 9% over thirty years is dramatic, which is the whole point of starting early.

This projection is in nominal terms — it does not subtract inflation. A corpus that looks large in today’s eyes will buy less decades from now, so treat the headline figure as a future-money number. A common way to sanity-check it is to lower your expected return by your assumed inflation rate to get a rough real (inflation-adjusted) growth rate, then read the result as today’s purchasing power.

The tax-advantaged account you actually save through varies by country. In the US that might be a 401(k) or an IRA; in India the NPS, EPF, or PPF; in the UK a pension or ISA; in Australia superannuation. Each has its own contribution limits, employer-match rules, and tax treatment, and any employer match is effectively free return on top of what this calculator shows. The math here is account-agnostic — it models the growth of whatever you contribute — so layer your local account rules on top.

Once you reach the corpus, the question becomes how much you can safely draw each year without running out. A widely cited starting point is the 4% rule, which this tool applies to your projected corpus to estimate a first-year sustainable income.

A 30-year-old with 50,000 already saved, adding 500 a month, expecting an 8% annual return, retiring at 60: that is 30 years, or 360 months, at a monthly rate of 8% ÷ 12 ≈ 0.667%. The existing 50,000 grows to about 547,000, and the 500-a-month stream grows to about 745,000, for a projected corpus of roughly 1,292,000. You will have contributed 230,000 of your own money (50,000 plus 360 × 500), meaning over a million of the total is investment growth. Under the 4% rule, that corpus could provide around 51,700 in first-year retirement income before inflation.

Projections this far out are estimates, not promises. Returns are not smooth — a market slump in the years just before or just after retirement (sequence-of-returns risk) can hurt far more than the same slump mid-career, so the 4% rule is a rule of thumb rather than a guarantee and many planners now suggest a more conservative withdrawal rate. The model also assumes contributions stay flat; in reality you may step them up as your income grows, which lifts the corpus substantially. And because the figure is pre-inflation and pre-tax, discount it for both before judging whether it is enough.