One tool, the whole retirement arc
Most retirement maths answers half a question. A savings or investment calculator grows a pot and stops at the finish line; a payout calculator starts from a lump sum that has already been built and asks how it pays out. This page joins both halves: it grows your current savings and monthly contribution to a retirement age you choose, then keeps the same money moving, drawing the yearly income you ask for while whatever is left keeps earning a return, until either the pot runs dry or it plainly does not. The headline above is a single honest answer to "am I on track": the age your own numbers actually get you to.
How the growth phase is worked out
From today until retirement, the pot compounds every month: whatever it earned that month is added, then that month's contribution lands on top. The same formula behind any regular savings plan applies here, run for the number of months between your current age and your retirement age:
Take the calculator's own defaults: $15,000 saved already, $250 added every month, growing at 6% a year from age 30 to 65, 420 months. That reaches $478,031 by retirement, of which $120,000 was actually paid in (the $15,000 start plus 35 years of $250 months) and $358,031 is growth on top. At 0% growth the formula collapses to plain addition, savings plus contribution times the number of months, with nothing compounding at all.
How the drawdown phase is worked out
From retirement onward, the same balance keeps earning the same rate while a fixed yearly income, split into equal monthly amounts, comes out of it. That is the mirror image of the growth phase, and like any pot paying out a fixed sum while what remains still earns a return, it has an exact point at which it reaches zero, found the same way this site's Annuity Payout Calculator finds it, by logarithm:
On the calculator's own numbers, that $478,031 pot drawing $36,000 a year at 6% lasts a further 319.4 months, just over 26 and a half years, reaching age 91.6, which rounds to the age 92 the headline reports. Set a bigger income or a smaller pot and that number falls; ask for less than the pot earns every month on its own, here $2,390.15 a month, and there is no month at which it reaches zero at all, the pot lasting indefinitely instead, a case this calculator states plainly rather than inventing an ending. At 0% growth the logarithm is not needed either: months until depleted is simply the pot divided by the monthly income.
The verdict, against a target age you set
The headline above compares the age your pot actually reaches with the target age you choose, a planning figure, not a claim about how long anyone will live. Set it to whatever number matters to your own plan, a parent's age at death, a round number like 90, or a country's average life expectancy looked up separately. Land past it and the headline reads as a pass, your pot lasting to the age it works out to; fall short and it reads as a shortfall, the age it actually runs out at, so the news is never softened either way.
What the required-saving figure actually solves
Under the main verdict sits a single actionable number: the monthly contribution, added from today, that makes the pot last to exactly the target age chosen, holding your current savings, retirement age, return and desired income fixed and solving for the one figure you can most directly change. It is found by narrowing in on the contribution that makes the depletion age above land on the target, the same kind of search this site's Savings Calculator uses to solve for a deposit instead of a date. On the calculator's own numbers, reaching age 90 needs only $241.29 a month, less than the $250 already being saved, which is exactly why the main plan clears age 90 with room to spare and lands at 92 instead. The table alongside it repeats the same solve for a spread of nearby target ages, from $164.00 a month for age 80 up to $283.77 a month for age 100, so a slightly longer or shorter goal can be priced without moving any slider.
The 4% rule, as a cross-check, hedged
The "check your number" table alongside the chart lines your own desired income up against a well-known rule of thumb: draw 4% of a pot in the first year of retirement and adjust that amount for inflation every year after, a figure tracing to financial planner William Bengen's 1994 study in the Journal of Financial Planning, tested further by Cooley, Hubbard and Walz's 1998 Trinity study. On the calculator's own $478,031 pot, that works out to $19,121 in the first year, well under the $36,000 actually asked for, one honest way of seeing why this particular plan depletes rather than lasting indefinitely. That rule models a real, varying sequence of historical market returns over a rolling 30-year retirement with an inflation-adjusted withdrawal; this calculator instead uses one constant return and a flat, non-inflating income, so the two figures are a useful cross-check, not the same calculation. The table also shows the income the pot could pay out forever by drawing only its growth, never touching the principal, $28,682 a year here, the exact boundary this page's own drawdown maths uses to decide whether a pot depletes at all.
The 80% convention: how much income retirement actually needs
Not everyone arrives at a desired income figure from scratch. A long-standing rule of thumb in financial planning holds that most people need somewhere around 70 to 80% of their pre-retirement income to keep roughly the same standard of living once they stop working, since costs such as commuting, pension contributions and, often, a mortgage tend to fall away. The "Use 80% of my income" button applies that convention to whatever figure is entered as current annual income, as a starting point to adjust, not a fixed answer: lower earners often need to replace closer to the whole of their income just to cover essentials, while higher earners can usually get by on a smaller share.
The inflation lens: today's money
A pot several decades away is a number that buys less by the time it exists, because prices rise in the meantime. Switching the lens on divides the projected pot at retirement by inflation compounded over every year between now and then, the standard way to restate a future sum in today's purchasing power, exactly the method this site's Annuity Calculator uses for the same question. It changes only that one figure; the drawdown timeline and the depletion age keep working in flat, non-inflating terms throughout, the same convention the Annuity Payout Calculator uses for withdrawals, so the two halves of this page stay internally consistent with each other.
Sequence-of-returns risk, briefly
A single steady return hides something a real, varying sequence of returns cannot: a fall in the years just before or just after retirement does far more damage than the same fall averaged in a decade later, because withdrawals taken from a pot that has just dropped never get the chance to recover. This calculator's constant rate cannot show that risk, since every year behaves identically by construction; it is a real feature of drawing an income from a pot, not something this page's arithmetic models.
Choosing your numbers and reading the results
Current savings is whatever is already set aside for retirement across any account; monthly contribution is what is actually being added now, not an aspiration. The expected return is a single planning assumption applied before and after retirement alike, worth testing at a lower figure alongside your best guess since a real portfolio rarely returns the same amount every year. Desired income is what a year of retirement should actually pay, in today's money, and the target age is the length of retirement the whole plan is being measured against. The chart plots the full arc, balance rising through the working years and falling through retirement, with a marker where the two phases meet; the year-by-year table underneath gives the same figures a row at a time, thinned to a readable length on a long plan while always keeping the final row.
Questions people ask
What happens if my desired income is less than the pot's own growth?
The pot lasts indefinitely. If the yearly income asked for is at or below what the pot earns in a year at the assumed return, the balance holds steady or keeps growing instead of ever falling to zero, and the verdict says so plainly rather than inventing a depletion age.
What if I set a desired income of zero?
With nothing being drawn out, the pot simply keeps growing after retirement rather than ever running down, so there is no depletion age to report. Set a real income figure, or use the 80% button, to see how a genuine withdrawal plan holds up instead.
Can I set a retirement age before my current age?
No. Retirement age is kept at least one year ahead of current age automatically; if the current age slider is moved past it, retirement age is nudged up to stay valid rather than letting the maths run on a negative or zero-length working life.
Is the required-saving figure the same as the 4% rule?
No, they answer different questions. The required-saving figure solves for the monthly contribution that makes your own pot, at your own assumed return, last to the target age you set. The 4% rule is a separate, historically derived rule of thumb shown alongside it as a sanity check, built from real market data rather than your own inputs.
Does this account for tax, pensions or state benefits?
No. Every figure here is the arithmetic on a single pot, before any tax on withdrawals, employer pension contributions, state pension, Social Security or other income that might sit alongside it in a real retirement plan. Add those separately when judging whether the target age is realistic.
Is 90 the right target age to use?
There is no universally right answer; 90 is offered as a round, cautious default, not a calculated life expectancy. Adjusting it to a figure that matches your own family history, a national life-expectancy table, or simply a personal comfort margin will give a more meaningful verdict than leaving the default in place.
Why does the return stay the same before and after retirement?
To keep the maths in one place and easy to check by hand. Many real plans shift to a more cautious mix of investments at or near retirement, which would lower the return used during drawdown; testing the calculator twice, once at your working-years return and again at a more cautious retirement-years return, shows the effect of that kind of shift.
This calculator gives an estimate based on one constant assumed return, a flat non-inflating income and no tax, pension or state-benefit adjustments; it is not financial advice. Real markets rise and fall from year to year, and the order those returns arrive in matters as much as their average. Speak to a regulated financial adviser before making retirement decisions.