Retirement Savings Calculator: Future Balance and Real Value
Knowing whether you are on track for retirement requires projecting your savings into the future and then adjusting for inflation so you understand what those dollars will actually buy. This calculator uses the standard future value formula to project both a lump-sum current balance and ongoing monthly contributions forward to your retirement date. It then deflates the result by your expected inflation rate to express the balance in today's purchasing power. Finally, it applies the 4% withdrawal rate guideline to estimate how much monthly income your projected portfolio could support. Enter your current retirement savings, the amount you contribute each month, your expected average annual investment return, the number of years until you retire, and your expected annual inflation rate. The outputs show your nominal projected balance, the inflation-adjusted value in today's dollars, and the estimated monthly income both in nominal and real terms. The contribution and growth breakdown shows how much of your projected balance comes from money you save versus investment returns, helping you understand the power of compounding over long time horizons.
Formulas
r = annual return / 12 (monthly rate)
n = years x 12 (total months)
FV of current savings = current x (1 + r)^n
FV of contributions = monthly x ((1 + r)^n - 1) / r
Total nominal balance = FV of savings + FV of contributions
Real (inflation-adjusted) balance = nominal / (1 + inflation)^years
Monthly income (4% rule, nominal) = nominal balance x 0.04 / 12
Monthly income (4% rule, real) = real balance x 0.04 / 12
Total contributions = current savings + (monthly x n)
Investment growth = nominal balance - total contributions
How to use this calculator
- Enter your total current retirement savings across all accounts (401k, IRA, brokerage, etc.).
- Enter the total monthly amount you contribute to retirement accounts.
- Enter your expected average annual investment return. A figure of 6% to 7% is commonly used for a balanced portfolio.
- Enter the number of years until you plan to retire.
- Enter your expected average annual inflation rate (the Federal Reserve targets 2%; 3% is a conservative planning figure).
- Read your nominal and real projected balances and the estimated monthly income each would support at a 4% withdrawal rate.
Frequently asked questions
What is the 4% withdrawal rule?
The 4% rule is a retirement spending guideline suggesting you can withdraw 4% of your portfolio in the first year of retirement, then adjust for inflation annually, and have a high probability of not running out of money over a 30-year retirement. It originated from the 1994 Trinity Study. It is a rule of thumb, not a guarantee, and some financial planners now suggest 3% to 3.5% given lower expected future returns.
What return rate should I use?
Historical US stock market returns have averaged roughly 10% nominally (about 7% after inflation) over long periods. A balanced portfolio (60% stocks, 40% bonds) has historically returned around 7% to 8% nominally. Use a conservative figure (6% to 7%) for planning purposes. The Federal Reserve and academic research suggest future returns may be lower than historical averages.
What does inflation-adjusted value mean?
The inflation-adjusted (real) value shows what your projected balance would be worth in today's purchasing power. If your nominal balance is $1 million in 25 years but inflation averages 3% per year, that $1 million will only buy what about $477,000 buys today. Always plan in real terms to avoid overestimating your future standard of living.
How does the monthly contribution frequency affect results?
This calculator assumes monthly contributions made at the end of each month. If you contribute biweekly or weekly, your actual result may be slightly higher due to more frequent compounding opportunities. The difference is small for planning purposes.
Should Social Security income be included?
This calculator shows only your personal savings and investment portfolio. Social Security benefits provide additional income in retirement and should be added to your projected monthly income. Estimate your Social Security benefit using the SSA's online tools at ssa.gov.
Official sources
- SSA: Retirement Benefits: ssa.gov/retirement/.
- IRS: Retirement Plans: irs.gov/retirement-plans.
- CFPB: Planning for Retirement: consumerfinance.gov/consumer-tools/retirement/.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.