How your retirement pot grows
This projects the same compounding that drives any long-term investment: your current savings grow at the expected return, and every monthly contribution you add grows too, for as long as it stays invested. Over decades, the growth ("interest on interest") often ends up larger than everything you put in — which the chart makes clear as the curve steepens toward retirement.
Why starting early matters so much
Because compounding rewards time, a contribution made at 25 has far longer to grow than the same amount at 45. Small monthly amounts started early frequently beat larger amounts started late. Try nudging the current age or the monthly figure and watch how much the final pot moves.
The 4% rule for income
A common rule of thumb suggests you can withdraw about 4% of your pot in the first year of retirement, adjusting for inflation after that, with a reasonable chance the money lasts ~30 years. The tool shows roughly what monthly income that implies, as a rough guide — real planning should account for inflation, taxes, fees and your own risk tolerance.
Note: this is a simplified educational estimate, not financial advice. Returns aren't guaranteed and inflation reduces future purchasing power.
Frequently asked questions
What return should I assume?
Long-run diversified portfolios have historically returned mid-single-digits after inflation, but nothing is guaranteed. Use a conservative figure and try a range to see the spread of outcomes.
Is the result in today's money?
It's a nominal figure. To think in today's purchasing power, use a return net of your expected inflation rate.
How much do I need to retire?
A common rule is to save about 25 times your annual spending, so you can withdraw around 4% a year. The tool projects your savings from contributions and returns.
How much should I save each month?
It depends on your age and goal; the earlier you start, the less you need to contribute thanks to compound growth.
What is the 4% rule?
It suggests you can withdraw 4% of your savings in the first year (adjusting for inflation) with a low chance of running out over about a 30-year retirement.