How to use this retirement calculator
- Current age and retirement age — the gap is how many years your savings have to grow.
- Current retirement savings — the combined balance of your 401(k), IRA and other accounts set aside for retirement.
- Monthly contribution — what goes in each month, including any employer match.
- Expected annual return — your assumed average yearly investment return before inflation.
- Expected inflation — used to express the result in today's purchasing power.
- Yearly contribution increase — optional; models raising your savings as your pay grows.
How the projection works
Each year has twelve monthly contributions, added at the end of each month. The annual return is converted to its monthly equivalent, (1 + r)1/12 − 1, so a balance with no new deposits grows by exactly the annual return each year. After every year the monthly contribution rises by the increase you entered. Finally, the balance is converted to today's dollars by dividing by (1 + inflation)years.
Worked example
You are 35 with $50,000 saved and contribute $500 a month, raising that by 2% each year. You expect a 7% return and 3% inflation, and plan to retire at 67 — 32 years away.
- Projected balance at 67: $1,281,428.
- Of that, $315,362 is money you put in; the remaining $966,066 is investment growth.
- In today's dollars, the balance is worth about $497,626.
- Under the 4% rule that supports roughly $19,905 a year ($1,659 a month) in today's money, on top of Social Security or a pension.
Why starting early matters
Saving $500 a month at a 7% annual return until age 67, starting with nothing:
| Start age | Years saving | You contribute | Balance at 67 |
|---|---|---|---|
| 25 | 42 | $252,000 | $1,427,648 |
| 35 | 32 | $192,000 | $682,267 |
| 45 | 22 | $132,000 | $303,353 |
| 55 | 12 | $72,000 | $110,732 |
Starting at 25 instead of 35 means contributing $60,000 more, but it roughly doubles the final balance. The extra decade of compounding does most of the work.
The 4% rule, explained
The 4% rule comes from financial planner William Bengen's 1994 study of historical U.S. stock and bond returns. It suggests you can withdraw 4% of your savings in the first year of retirement, then raise that dollar amount each year for inflation, and historically the money would have lasted at least 30 years in every period he tested.
It is a rule of thumb, not a guarantee:
- It assumes roughly a 30-year retirement. Retiring early means your money must last longer, and many planners use a lower withdrawal rate for that.
- It depends on your mix of investments, fees and the order in which good and bad years arrive — a market crash early in retirement does more damage than one later.
- Future returns may differ from the past.
Turned around, the rule gives a quick target: multiply the yearly income you want from savings by 25. Needing $40,000 a year from your portfolio implies about $1,000,000 saved.
Why inflation matters
At 3% inflation, prices double in roughly 23 to 24 years. A million dollars three decades from now will buy far less than a million dollars today, so judge your plan by the "today's dollars" figure rather than the larger nominal number.
Ways to close a gap
- Collect your full employer match — it is an immediate return on your money. See our 401(k) calculator.
- Raise contributions with each pay raise so your take-home pay never drops.
- Work a few years longer. It adds contributions, adds growth and shortens the time your savings must last.
- Keep fees low. A fund charging 1% a year more than another reduces your return by that full amount every year.
- Check your Social Security estimate at ssa.gov to see how much income you can expect outside your savings.
These figures are estimates for planning, not investment advice. A fee-only financial planner can build a plan around your full situation.
Frequently asked questions
How much do I need to retire?
A common starting point is 25 times the yearly income you will need from savings, which follows from the 4% rule. Subtract expected Social Security and pension income from your yearly spending before multiplying.
What return should I assume?
There is no guaranteed rate for investments. Many people run their plan at a few different rates — for example 5%, 6% and 7% — to see a range of outcomes rather than relying on one number.
Does this calculator include Social Security?
No. It only projects your own savings. Your Social Security benefit is additional income; you can get a personal estimate from the Social Security Administration at ssa.gov.
What is the difference between nominal and today’s dollars?
Nominal dollars are the actual number of dollars in your account in the future. Today’s dollars adjust that number for inflation, so you can judge what it would buy at current prices.
Is the 4% rule safe?
It held up in historical U.S. data for 30-year retirements, but it is a guideline, not a promise. Longer retirements, high fees or poor returns early in retirement can make 4% too high. Many retirees adjust their withdrawals as markets change.
Last updated: October 8, 2026