Retirement Age Calculator
Enter what you've saved, what you add monthly, and what retirement costs per year — and get the age your portfolio is projected to support it, plus the target it has to hit.
Educational estimates only. This calculator is for planning and education. It is not financial, tax, or investment advice, and results may differ from what a lender, broker, or the IRS calculates for your situation. Confirm important decisions with a qualified professional.
How this calculator works
Two pieces of arithmetic joined together. First, the spending target becomes a nest-egg target through the withdrawal-rate rule: a portfolio supports annual withdrawals of a chosen percentage, so the nest egg must be spending divided by that rate — $60,000 a year at 4% means $1.5 million. Second, the calculator grows your current savings month by month, adding contributions and compound growth, until the balance crosses the target. The crossing month, added to your current age, is the projected retirement age.
Every input is deliberately visible rather than baked in — the withdrawal rate is editable because 4% is a historical rule of thumb, not a guarantee, and the return field accepts whatever assumption you consider honest. The most useful way to use this page is to run it three times — pessimistic, expected, optimistic — and plan around the range.
The formula
Target nest egg = annual spending ÷ withdrawal rate Each month: balance = balance × (1 + r/12) + contribution Retirement age = current age + months-to-target ÷ 12
The withdrawal-rate framing comes from William Bengen's 1994 paper "Determining Withdrawal Rates Using Historical Data" (Journal of Financial Planning) and the 1998 Trinity University study that popularized the 4% figure using historical US market data. The accumulation math is the standard future-value-of-an-annuity recursion — the same engine as the compound interest calculator.
Worked example
Say you're 30 with $50,000 saved, adding $1,000/month, assuming 7% growth, aiming to spend $60,000/yr at a 4% withdrawal rate:
- Target: 60,000 ÷ 0.04 = $1,500,000
- Grow $50,000 at 0.5833%/month plus $1,000 deposits…
- The balance crosses $1.5M after 348 months = 29 years
- Projected retirement age: 30 + 29 = 59, having added $348,000 in contributions along the way
Rerun it at a 5% return and the age slides to about 65; at $1,500 a month it drops near 55. The inputs you control — contributions and spending — move the answer as much as the market does.
Assumptions & tips
- Spending is the lever squared. Cutting $10,000 from annual retirement spending removes $250,000 from the target at 4% — and usually means you're saving more meanwhile. No return assumption works that hard.
- Subtract guaranteed income first. Social Security, pensions, and annuity income reduce what the portfolio must fund. Enter only the portfolio's share of spending.
- Mind the early-retirement gauntlet. Retiring before 59½ raises account-access questions and before 65, healthcare costs. The math here is necessary, not sufficient — the 401k early withdrawal calculator covers one of the traps.
- Sequence risk is real. The withdrawal-rate studies assume you stay the course through bad early years. A flexible spending plan (skip inflation raises in down years) materially improves survival odds in the same historical data.
- Revisit annually, not daily. One fresh run a year with real balances beats daily tinkering with assumptions — the projection converges on reality as the horizon shortens.
Frequently asked questions
Where does the 4% withdrawal rate come from?
From William Bengen's 1994 study in the Journal of Financial Planning and the 1998 "Trinity study" by three Trinity University professors, which tested withdrawal rates against every historical 30-year US market period. A portfolio of stocks and bonds survived 30 years of inflation-adjusted 4 percent withdrawals in nearly every period tested. It is a historical observation about US markets, not a law of nature — many planners now model 3.5 to 4.5 percent depending on retirement length and flexibility.
Should I use a real or nominal return?
For this calculator, a real (after-inflation) return paired with today's spending gives the most honest answer: your spending target is in today's dollars, so the growth rate should be too. If you expect 7 percent nominal growth and 3 percent inflation, enter about 4 percent. Entering 7 percent with today's spending quietly assumes your expenses never inflate — the most common way these projections mislead.
What does the calculator assume about Social Security and pensions?
Nothing — deliberately. Any guaranteed income reduces the savings your portfolio must cover: subtract it from your annual spending before entering the number. If you'll spend 60,000 dollars and expect 24,000 from Social Security, your portfolio only needs to fund 36,000 — which cuts the target nest egg from 1.5 million to 900,000 at a 4 percent withdrawal rate.
Why does a small return change move the answer so much?
Because the return works on both sides: it grows the balance toward the target and it compounds every future contribution. Dropping the worked example from 7 to 5 percent pushes retirement from 59 to about 65 — six years for two points. That sensitivity is the honest takeaway: treat the answer as a range across plausible returns, not a date to circle.
Is retiring at the computed age actually feasible?
The math finds when your nest egg covers your spending — feasibility involves more: healthcare before Medicare eligibility at 65, penalty rules on retirement accounts before 59½ (see the 401k early withdrawal calculator), sequence-of-returns risk in the first years, and whether your spending estimate survives contact with reality. Treat this as the arithmetic backbone of a plan a professional helps you stress-test, not the plan itself.
Sources
- Determining Withdrawal Rates Using Historical Data — William P. Bengen, Journal of Financial Planning, October 1994; reprinted by the Financial Planning Association in its Best of 25 Years series, 2004. financialplanningassociation.orgThe original safe-withdrawal-rate study that the 4% default and the spending-divided-by-rate target both rest on.
- Retirement Savings: Choosing a Withdrawal Rate That Is Sustainable — Philip L. Cooley, Carl M. Hubbard and Daniel T. Walz, Trinity University; AAII Journal, February 1998. aaii.comThe Trinity study named in the FAQ and formula notes: portfolio success rates for a range of withdrawal rates across historical 15-to-30-year payout periods.
- Topic no. 558, Additional tax on early distributions from retirement plans other than IRAs — Internal Revenue Service. irs.govThe age-59½ threshold behind the early-retirement account-access warning in the FAQ and tips.
- Get started with Medicare — Medicare.gov, Centers for Medicare and Medicaid Services. medicare.govConfirms the age-65 Medicare eligibility that defines the healthcare gap the FAQ flags for anyone retiring earlier.
- Retirement Benefits, SSA Publication No. 05-10035 — U.S. Social Security Administration, 2026 edition. Where to find the guaranteed Social Security income this page tells you to subtract from spending before entering it.
Related calculators
Tithing Calculator
A tithe per paycheck and per year, on gross or take-home pay — plus what it actually costs you after tax.
Mortgage Calculator
Full monthly payment — principal & interest plus taxes, insurance, PMI, and HOA — with a breakdown chart, amortization schedule, and payoff date.
Mortgage Payoff Calculator
See how extra monthly or one-time payments change your payoff date and total interest — with a chart.
Biweekly Mortgage Calculator
Compare a standard monthly schedule against biweekly half-payments — time and interest saved.