Calculator Inputs
yrs
Your age today.
yrs
The age at which you plan to retire.
$
Total retirement savings today (401k, IRA, brokerage, etc.).
$
How much you invest toward retirement each month.
%
Assumed average annual portfolio return. S&P 500 historical: ~10% nominal, ~7% real.
%
Long-run inflation rate. US historical average: ~3%. Fed target: 2%.
$
Estimated monthly spending in today's dollars. Calculator adjusts for inflation.
⚠ Shortfall of $1.84M — you need $2,024/mo to reach the required corpus
Results
Projected Savings
$2.38M
At age 65
Required Corpus (4% rule)
$4.22M
25× annual expenses (inflation-adj.)
Est. Monthly Retirement Income
$12,543
Sustainable for 25 yrs
Inflation-Adj. Monthly Expenses
$14,069
In 65-age dollars
Surplus / Shortfall
-$1.84M
Years to Retirement
35 years
Savings Projection vs Required Corpus
Return Rate Scenarios
Your projected savings under pessimistic, base, and optimistic return assumptions.
| Scenario | Annual Return | Projected Savings | Required Corpus | Gap / Surplus | On Track? |
|---|---|---|---|---|---|
| Pessimistic | 5.00% | $1.42M | $4.22M | -$2.80M | ✗ No |
| Base | 7.00% | $2.38M | $4.22M | -$1.84M | ✗ No |
| Optimistic | 9.00% | $4.09M | $4.22M | -$125,840 | ✗ No |
Savings Growth by Age
| Age | Year | Projected Savings | Total Contributed | Investment Gains |
|---|---|---|---|---|
| 35 | 2031 | $142,474 | $110,000 | $32,474 |
| 40 | 2036 | $273,568 | $170,000 | $103,568 |
| 45 | 2041 | $459,410 | $230,000 | $229,410 |
| 50 | 2046 | $722,864 | $290,000 | $432,864 |
| 55 | 2051 | $1.10M | $350,000 | $746,343 |
| 60 | 2056 | $1.63M | $410,000 | $1.22M |
| 65 | 2061 | $2.38M | $470,000 | $1.91M |
The 4% Rule
The 4% rule (Bengen Rule) states you can safely withdraw 4% of your portfolio in year one, then adjust for inflation each year, with a historically very low probability of running out of money over 30 years. A required corpus of 25× annual expenses follows directly: 1 / 0.04 = 25.
Real Return vs Nominal Return
Nominal return is what your portfolio earns before inflation. Real return = nominal − inflation. At 7% nominal and 3% inflation, your real return is 4%. This calculator uses nominal return during accumulation and real return during retirement income estimation.
Why Monthly Contributions Matter More Than Return
For most investors in accumulation phase, contribution rate dominates. Doubling your monthly contribution from $500 to $1,000 has more impact than increasing your expected return from 7% to 10% — especially in the first 15 years. Control what you can control.
Retirement Income Shortfalls
If your projected savings fall short, the main levers are: (1) increase monthly contributions, (2) retire later, (3) reduce planned retirement spending, or (4) take on slightly more equity exposure to improve expected returns. Social Security is not modeled here — add it to your monthly income estimate.
* This calculator is for educational purposes only and does not constitute financial advice. Results assume constant returns and inflation, which will vary in practice. Consult a certified financial planner for personalized retirement planning.