How your retirement pot builds up
Retirement saving is really a compounding story. This calculator takes what you have saved today, adds a fixed amount every month until you retire, and lets the whole balance grow at your expected return. Then it estimates the income that pot could pay you using the 4% rule, a well-known guideline that says you can withdraw roughly 4% of your savings in the first year and adjust for inflation after that.
The striking part is how little of the final number comes from your own pocket. Over a few decades, growth on top of growth does most of the heavy lifting, and the money you added in your twenties and thirties ends up worth far more than the money you add near the end.
Two examples
Start at 35 and save 500 a month until 65 at a 7% return. The pot grows to roughly half a million, and most of that is investment growth rather than the contributions you made. At 4%, that supports around 1,600 a month of income.
Now imagine starting the same 500 a month at 25 instead of 35. That single decade of extra compounding can push the pot toward a million, close to double, for only ten more years of saving. The lesson is blunt: when you start beats how much you save.
Getting more out of it
- Start now, even if the amount is small. Time in the market is the one lever you cannot buy back later.
- Raise your contribution whenever your income rises. A yearly bump you barely notice adds up massively over decades.
- Capture any employer match in full. It is an instant return you will not find anywhere else.
Read the result carefully
These are nominal figures, before inflation and tax. Half a million in 30 years will not buy what it does today, so use the inflation calculator alongside this to see the real buying power. The 4% rule is a rule of thumb, not a promise, and markets fall as well as rise. Treat the number as a target to steer by, not a guarantee.
Frequently asked questions
Why does starting early matter so much?
The earliest money compounds the longest. Starting ten years sooner can roughly double the final pot for the same monthly saving.
Should I include my employer match?
If your employer matches contributions, add it to your monthly amount. It is effectively free money and an instant return.
What is the 4% rule?
A rule of thumb that you can withdraw about 4% of your retirement savings per year with a good chance the money lasts 30 years. It is a guide, not a guarantee.
What return should I assume?
Be realistic. Long-term diversified investments have historically returned mid-single digits after inflation, but returns are never guaranteed.
Does this include inflation or tax?
No. It shows nominal (before-inflation, before-tax) figures. Use the inflation calculator to see future buying power.