How This Retirement Calculator Works
This calculator projects your nest egg using the compound interest formula, with monthly contributions. It takes your current savings, grows them by your expected annual return, and adds each monthly contribution on top — all compounded until your retirement age.
The projection assumes a constant monthly return. Real markets don't work that way, so treat the result as a realistic baseline, not a promise. Run the numbers with a conservative return (5-6%) and a more optimistic one (8%) to see the range of possible outcomes.
What "Enough" Actually Means
The classic rule is the 4% rule: you can safely withdraw about 4% of your portfolio in the first year of retirement and adjust for inflation after that. Flip it around and you get the "25x" target — you need roughly 25 times your annual spending saved. If you plan to spend $50,000 a year, aim for about $1.25 million.
If this calculator says you're short, the levers are simple: save more monthly, retire later, or plan to spend less. Saving more is the most powerful lever, and starting early beats everything — the same monthly contribution invested at 25 compounds to far more than one started at 45.
Start Early, Even Small
The math rewards time more than amount. A $200 monthly contribution from age 25 to 65 at 7% becomes roughly $480,000. The same $200 started at 45 becomes about $105,000. The difference is time in the market, not a higher salary.