- The answer here is a year, not a balance — the age your savings run out at the spending you set.
- Traditional withdrawals are grossed up: putting $60,000 in your pocket takes roughly $70,000 out of the account.
- Social Security reshapes the plan — once it starts it replaces most of a modest spending target dollar for dollar.
- Changing the spending target moves the depletion age more than changing the return assumption does.
How this retirement projection works
Most retirement calculators stop at a balance. This one starts there and spends it. Enter your birth year, the annual spending you want, your filing status and what you hold in traditional and Roth accounts, and it steps forward a year at a time to your life expectancy — reporting the age the money runs out, or that it never does.
Each year the portfolio grows at the return you choose, the spending target rises with inflation, and Social Security arrives at the claiming age you elect. Whatever that benefit does not cover is withdrawn, and the withdrawal is grossed up so that what lands in your account after tax is what you asked to spend.
Nothing is contributed here — this is the drawdown side of the plan, not the saving side. Advanced assumptions let you change your life expectancy, your expected return, your claiming age and your benefit at full retirement age, and the balance-by-age table under the chart shows the same projection row by row rather than only as a curve.
The math
The projection runs in nominal dollars on an annual step. Balances grow at the nominal return behind the Low, Medium and High presets — 4%, 6% and 7.5% — and the spending target is escalated 2.5% a year, so late rows are future dollars rather than today’s.
Mandatory income settles first: Social Security from the claiming age you elect, adjusted up for delaying past full retirement age and down for claiming early, plus required minimum distributions from traditional accounts once you turn 73. The rest of the cash need is met by a grossed-up withdrawal — the engine solves for the gross amount whose after-tax remainder equals what is still needed — drawn from taxable accounts, then traditional, then Roth. Tax is federal brackets with the standard deduction, the provisional-income formula that decides how much of the benefit is taxable, and a flat 5% state rate.
Two limits worth stating plainly. Bracket and deduction thresholds are taken from a frozen base-year table indexed forward by the inflation rate you set, not from the current published tables the take-home calculator on this site uses. And one fixed return every year says nothing about sequence risk: a bad first decade is far worse than the same average arriving late.
Worked example
The defaults describe a single filer in their early sixties with $400,000 in a traditional 401(k) or IRA, $100,000 in a Roth and $60,000 a year to spend, planning to 92 at a 6% return. To put $60,000 in their pocket in the first year the calculator withdraws about $70,000 from the traditional account — roughly $10,000 of it goes to tax — and closes the year at about $456,000.
The money lasts about ten years. A $2,200 monthly benefit claimed at 67 covers a large share of the target once it starts and the withdrawals drop sharply, but half a million dollars spending $60,000 a year does not stretch to 92. That is the useful answer: a year, not a balance. Lower the spending target or delay the claiming age and watch which one moves that year further.
Key terms
- Withdrawal order
- Which account gets drawn first. This projection uses taxable accounts, then traditional 401(k) and IRA balances, then Roth — the conventional default, which leaves tax-free growth compounding longest.
- Required minimum distribution (RMD)
- From age 73 a set share of your prior year-end traditional balance has to come out annually whether you need it or not — about 3.8% at 73, rising every year after. Roth IRAs are exempt while the owner is alive.
- Provisional income
- The measure that decides how much of your Social Security benefit is taxable — other income plus half the benefit. Cross its thresholds and up to 85% of the benefit joins your taxable income.
- Depletion age
- The age at which the projected portfolio can no longer fund the spending target. Past it, spending is whatever Social Security and any pension provide.