Project private savings growth to retirement with user-set return, inflation, tax, and withdrawal assumptions.
Building private savings outside of or alongside employer-sponsored retirement plans is essential for financial independence. Private savings in taxable brokerage accounts, IRAs, or other investment vehicles grow through compound interest — earning returns on your returns over time. The power of compounding means that starting early, even with small amounts, can lead to dramatically larger balances than starting later with more money.
Understanding how your savings translate into retirement income requires accounting for inflation, taxes, and sustainable withdrawal rates. The commonly cited 4% rule suggests withdrawing 4% of your portfolio annually in retirement, which historically has provided a 30-year safe withdrawal period. However, your actual retirement income depends heavily on your tax rate, inflation trajectory, and investment returns.
This calculator projects your private savings to your target retirement age, accounting for compound growth, inflation erosion, retirement taxes, and your desired withdrawal rate. It shows whether your savings plan achieves the common benchmark of replacing 80% of pre-retirement income.
Private savings plans are sensitive to assumptions that people usually underestimate, especially inflation, taxes in retirement, and the withdrawal rate used to turn a lump sum into income. This calculator puts those assumptions in one place so you can see whether a contribution plan supports the level of retirement income you are targeting.
Future Value = Current Savings × (1 + r)^n + Monthly × [((1 + r)^n − 1) / r] × (1 + r) Present Value = Future Value / (1 + inflation)^n Annual Withdrawal = Future Value × Withdrawal Rate After-Tax Income = Withdrawal × (1 − Tax Rate) Income Replacement = After-Tax Income / Current Income
Result: $1.38M at retirement
Starting at 35 with $75K saved and $1,000/month at 7% return: balance grows to ~$1.38M by age 65. At 4% withdrawal = $55,200/year. After 22% tax = $43,056/year ($3,588/month).
The nominal retirement balance is only part of the story. Inflation changes what that balance can actually buy, which is why the inflation-adjusted view is often more useful when you are comparing your future portfolio to today's spending level.
A retirement plan becomes easier to judge when the projected balance is converted into an annual withdrawal estimate. That income view lets you compare the portfolio to your current salary or target expenses instead of relying on a large lump-sum number that can feel reassuring but be hard to interpret.
Try a lower return, a higher inflation rate, or a more conservative withdrawal percentage. If the plan still replaces a workable share of income under those assumptions, the savings path is usually more resilient than one that only works under optimistic growth scenarios.
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This calculator projects a savings balance by compounding the current balance and the user's monthly contributions at a constant annual return assumption until the selected retirement age. It then discounts that future balance by the chosen inflation assumption, converts the balance to annual income using the selected withdrawal rate, and reduces that income by the user-entered retirement tax rate.
The 80% replacement target shown in the output is a planning benchmark built into this worksheet, not an official rule. The calculator does not predict market returns, Social Security benefits, pension income, sequence-of-returns risk, or future tax-law changes.
The 4% rule suggests withdrawing 4% of your portfolio in year one of retirement, then adjusting for inflation annually. Historical backtesting shows this approach sustains a portfolio for 30+ years in most market conditions.
A balanced portfolio (60/40 stocks/bonds) has historically returned 7-8% nominal. After inflation, real returns are typically 4-5%. Be conservative in planning — 6-7% is reasonable for a diversified portfolio.
At 3% inflation, $1 million in 30 years is worth about $412,000 in today's dollars. This is why the calculator shows both nominal future value and inflation-adjusted present value.
Financial advisors commonly recommend saving 15-20% of gross income for retirement. The higher your target, the earlier you can retire. FIRE movement advocates often save 50%+ of income.
Pre-tax (401k/Traditional IRA) saves taxes now but is taxed on withdrawal. Post-tax (Roth) uses after-tax dollars but grows tax-free. Generally, contribute to Roth when in lower brackets and pre-tax in higher brackets.
The common retirement planning benchmark is replacing 80% of pre-retirement income, assuming expenses drop (no commuting, no payroll taxes, no retirement contributions). Some may need more or less depending on lifestyle.