This free retirement calculator projects how your savings grow between now and your target retirement age using compound interest, then shows the result in both nominal and inflation-adjusted dollars along with your income at the 4% safe withdrawal rate. Enter your age, current savings, monthly contribution, expected return, and inflation assumption — the chart and figures update live, entirely in your browser.
The most-used rule of thumb is to save 25 times your desired annual retirement spending, which comes directly from the 4% safe withdrawal rule:
Retirement Number = Annual Spending ÷ 0.04 = Annual Spending × 25
Want $50,000 a year in retirement? You need about $1,250,000. Want $80,000? About $2,000,000. Retiring earlier — say at 55 instead of 65 — does not change the target much, but it gives your money a decade less to compound and a decade longer to last, so the required monthly contribution rises sharply.
Compound interest means your returns earn returns. The effect is exponential, so the when matters more than the how much. Here is $500 invested monthly at a 7% return, by the age you start:
| Start age | Value at 65 |
|---|---|
| 25 | ~$1,320,000 |
| 35 | ~$610,000 |
| 45 | ~$263,000 |
| 55 | ~$104,000 |
Each decade of delay roughly halves the outcome — not because you contributed less, but because compounding had less runway. This single table is the strongest argument for starting today with whatever you can.
A portfolio worth $2,000,000 in 30 years will not buy what $2,000,000 buys today. If inflation averages 3%, that future $2,000,000 is worth about $824,000 in today’s purchasing power. This calculator shows both figures so you plan against real spending power, not a headline number. Planning with real returns (your expected return minus inflation) is the honest way to avoid a nasty surprise.
You are 35, have $80,000 saved, and contribute $1,000 a month. At a 7% return you would reach roughly $1.6 million by 65 in nominal terms. At the 4% rule that supports about $64,000 a year — but after 30 years of 3% inflation, its real value is closer to $660,000, or about $26,000 a year in today’s money. Seeing both numbers is what stops people from over- or under-saving.
These are only signposts — your real answer comes from entering your own numbers and checking whether the projection crosses 25× your planned spending by your target age. If you prefer to plan without counting Social Security or a pension, simply treat the calculator’s income figure as your entire need.
What return rate should I use? Historically a diversified, stock-heavy portfolio has returned around 7% a year after inflation. Try a range (5%, 7%, 9%) to stress-test your plan.
Does it account for inflation? Yes — you set an inflation rate and the tool shows inflation-adjusted values alongside nominal ones.
Is my information private? Yes. Every calculation runs locally; nothing you enter is stored or transmitted.
Understand the fundamentals in The Power of Compound Interest and The 4% Rule Explained.
This tool is Step 5 of our master guide — The DIY Financial Plan: From First Dollar to Financial Independence.
Explore our other tools — FIRE Calculator, Mortgage Calculator, and Portfolio Stress-Tester. WealthDeck provides educational tools only, not financial advice — see our Terms & Disclaimer.