Savings target (4% rule)
$4,500,000
Spending $15,000 per month is $180,000 per year. Using the 4% rule you need about 25 times that — roughly $4,500,000. A more conservative 3.5% withdrawal rate pushes the target to about $5,142,857.
Open the calculator$4,500,000
25× annual spending
$5,142,857
~28.6× annual spending
$180,000
$3,600,000
20× — aggressive
The standard way to size a retirement portfolio is to work backwards from spending: annual spending divided by your withdrawal rate. That is where the popular "25× rule" comes from — 25 times annual expenses is the same thing as a 4% withdrawal rate.
Two things can shrink the target meaningfully. First, this is the portfolio needed to cover the full $15,000 per month; if Social Security or a pension covers part of it, you only need to fund the gap. Second, these are pre-tax figures — your account mix (Roth vs. traditional vs. taxable) determines how much of each withdrawal you keep.
| Withdrawal rate | Portfolio needed | Multiple of annual spending | Profile |
|---|---|---|---|
| 3% | $6,000,000 | 33× $180,000 | Very conservative |
| 3.5% | $5,142,857 | 28.6× $180,000 | Conservative |
| 4% | $4,500,000 | 25× $180,000 | The classic "4% rule" |
| 4.5% | $4,000,000 | 22.2× $180,000 | Slightly aggressive |
| 5% | $3,600,000 | 20× $180,000 | Aggressive |
A lower withdrawal rate means a bigger savings target but a wider safety margin. The 4% rule corresponds to saving 25 times your annual spending.
| Monthly contribution | Time to reach the target |
|---|---|
| $500 | More than 40 years |
| $1,000 | More than 40 years |
| $1,500 | More than 40 years |
| $2,000 | More than 40 years |
| $3,000 | More than 40 years |
Assumes a $10,000 starting balance, contributions held steady in today's dollars, and our standard return and inflation assumptions. Timeframes use the same projection engine as the main calculator.
If Social Security pays you, say, $2,000 per month, your portfolio only needs to produce $13,000 per month — which cuts the 4% savings target from $4,500,000 to about $3,900,000. Funding the gap, not the whole budget, is what your savings are for.
Withdrawing 4% per year is the same as holding 25 years' worth of spending (100 ÷ 4 = 25). The portfolio is invested while you draw it down, so growth replaces part of what you withdraw — historically enough to make $4,500,000 last 30 years or more at this spending level in most scenarios.
US household spending in retirement averages roughly $5,000 per month (BLS, households 65+), but the spread is wide: housing status, healthcare, and location dominate. Build the budget bottom-up from your own expenses, then use the multiplier to size the portfolio.
Yes, if your savings are mostly pre-tax. If you need $15,000 per month after tax and expect an effective tax rate of around 15% on withdrawals, you really need about $17,647 per month pre-tax — which raises the 4% target to roughly $5,294,118. Roth balances need no such adjustment.
A retirement of 40+ years argues for a withdrawal rate below 4%. At 3.5% the target for $15,000 per month is about $5,142,857, and at 3% about $6,000,000. Early retirees also need a plan for healthcare and for bridging the years before Social Security.
Open the full calculator with a $15,000/month withdrawal prefilled, then plug in your age, current savings, and contributions to see exactly when you'd get there.
Plan for $15,000/monthDisclaimer: This page is an educational estimate based on simplified assumptions, not financial advice. Market returns vary, and your taxes, fees, and personal circumstances will change the outcome. Consider consulting a qualified financial advisor before making retirement decisions.