Retirement Calculator Guide
"How much do I need to retire?" sounds like it should have one clean answer, but it depends heavily on a handful of assumptions — how long you'll live off the money, how it's invested, and how much you plan to spend each year. The retirement calculator does the compounding math for you; this guide covers the assumptions behind the numbers you feed it.
The 4% Rule (and Its Shortcut)
A widely cited starting point for retirement planning is the "4% rule": if you withdraw about 4% of your portfolio in your first year of retirement and adjust that amount for inflation each year after, a portfolio invested in a typical stock/bond mix has historically had a good chance of lasting 30 years. Flip that percentage around and you get a quick target: multiply your expected annual retirement spending by 25. Someone who expects to spend $50,000 a year in retirement would target roughly $1,250,000 saved. It's a rough guideline, not a guarantee — sequence-of-returns risk (a market downturn early in retirement) can strain even a well-funded plan — but it's a far better starting point than guessing.
The Inputs That Matter Most
In the retirement calculator, your expected annual return and your number of years until retirement do most of the heavy lifting, because compounding rewards time more than it rewards small differences in your monthly contribution. Someone who starts contributing at 25 needs a noticeably smaller monthly contribution to hit the same target as someone starting at 40, even accounting for the extra 15 years of contributions the later starter is missing — the earlier money simply has more time to grow. If the numbers look intimidating, try shifting your assumed retirement age back a few years before assuming you need to save dramatically more each month.
Where Employer Matching Fits In
If you have access to a 401(k) with an employer match, that match effectively boosts your contribution rate for free — money you'd otherwise have to save entirely on your own. Run your numbers through the 401(k) calculator to see how much faster your specific match accelerates your timeline before finalizing the contribution rate you plug into your overall retirement plan.