PiggyRetirement Calculator
Project your nest egg at retirement and the monthly income it could sustain using the 4% rule.
How this is calculated
Current savings and monthly contributions compound monthly until your retirement age. The income figure applies the 4% rule: withdrawing 4% of the balance in year one, divided by twelve for a monthly number.
Worked example: a 30-year-old with $35,000 saved adding $600 a month at 7% reaches $1,483,348 by age 65, which supports roughly $4,944 a month under the 4% rule.
Your situation
Nest egg projection
How the projection works
Your current savings and monthly contributions are compounded monthly at your expected return until retirement age. The income estimate uses the widely cited 4% rule: withdrawing 4% of the portfolio in the first year of retirement (then adjusting for inflation) has historically sustained a 30-year retirement in most market scenarios.
Where the 4% rule came from, and its limits
The rule originates in 1990s research testing withdrawal rates against historical US market returns, and it survived every thirty-year period in that data — including retirements beginning just before major crashes. That is a strong result, but it comes with conditions that are easy to forget: it assumes a diversified portfolio holding a substantial share of equities, thirty years rather than forty, and the discipline to keep withdrawing during downturns rather than selling out.
Recent work has questioned whether it travels well to today's conditions, and some researchers now favour 3.5% for early retirees or those planning beyond thirty years. Treat 4% as a planning anchor rather than a promise. The practical version of the rule is more useful than the precise number: you need roughly twenty-five times your annual spending, so cutting $500 a month from expected expenses reduces the target by about $150,000.
What this projection deliberately ignores
Three omissions matter. There is no inflation adjustment, so a projected $1.48 million at 65 buys what roughly $530,000 buys today at 3% inflation over thirty-five years — the number is large partly because future dollars are small. There is no Social Security, which replaces around 30–40% of pre-retirement income for average earners and can be worth several hundred thousand dollars in equivalent capital. And there is no tax: money in a traditional 401(k) or IRA is taxed on withdrawal, so a million dollars there is worth meaningfully less than a million in a Roth account.
The projection also assumes a steady return, which retirement portfolios do not deliver. The order of returns matters far more once you are withdrawing than while you are saving — a severe downturn in the first few years of retirement does lasting damage, because you sell assets at depressed prices to fund living costs and those shares never recover. This is sequence-of-returns risk, and it is the main reason planners shift toward bonds as retirement approaches.
The levers that actually move the number
Try changing one variable at a time and watch which ones matter. Delaying retirement by three years typically does more than a full percentage point of extra return, because it adds contributing years, removes withdrawal years and compounds the largest balance you will ever have. Raising the contribution rate beats chasing returns, because it is entirely within your control while the market is not. And starting earlier beats both, for reasons the compound interest calculator makes visible.
If you are self-employed, note that you have access to accounts with far higher limits than a standard IRA — a Solo 401(k) or SEP-IRA can absorb a large share of business profit, and contributions reduce this year's taxable income as well as funding retirement. Our quarterly tax calculator shows the immediate tax effect.