Project your nest egg in today's dollars, see the income it supports, and find the monthly contribution that closes the gap.
Projections assume a constant rate of return and a constant inflation rate — real markets do neither. The withdrawal rate is an empirical rule of thumb, not a guarantee that your money will last. This tool does not model taxes on withdrawals, required minimum distributions, or sequence-of-returns risk. Estimates only.
A projection that says “$2 million at retirement” is close to meaningless, because $2 million in thirty years buys far less than $2 million today. This calculator removes inflation from the return rate first — it uses the real return, not the headline one — so the balance you see is stated in the purchasing power you actually understand. The trade-off is that the numbers look smaller than other calculators. They are not pessimistic; they are comparable to your salary.
The solid line is what you put in. The shaded area above it is what the market adds — and on a long horizon it is the larger half.
A 32-year-old with $60,000 saved, contributing $600 a month, expecting 7% nominal growth and 2.5% inflation, retiring at 67.
Project retirement savings in today's purchasing power, see the income it supports at your withdrawal rate, and solve for the monthly contribution that closes the gap. Free, no signup.
A projection that says "$2 million at retirement" is close to meaningless, because $2 million in thirty years buys far less than $2 million today. This calculator removes inflation from the return rate before projecting — it compounds at the real return, not the headline one — so every figure is stated in the purchasing power you already understand. The numbers look smaller than other calculators produce. They are not pessimistic; they are comparable to your current salary.
If your portfolio earns 7% and inflation runs at 2.5%, your real return is not 7% − 2.5% = 4.5% but (1.07 ÷ 1.025) − 1 ≈ 4.39%. The difference looks trivial over one year and is not over thirty. Working in real terms also means you never have to guess what a future dollar will be worth — the target you set today stays the target, and the answer tells you directly whether your current saving rate gets you there.
The sustainable income figure comes from applying a withdrawal rate to your projected balance — 4% by default. That rate comes from the Trinity study and Bengen's original research, which examined how much a retiree could withdraw annually from a balanced portfolio without running out of money over a 30-year retirement. It is an empirical rule of thumb, not a guarantee. A lower rate is safer and implies a larger target; a higher rate means more income now and more risk later.
The calculator does not just tell you whether you are short — it solves for the monthly contribution that would close the gap, holding your return, inflation and horizon constant. That number is usually uncomfortably large, and that is the point: it converts a vague worry into a specific, checkable figure. Time is the strongest lever available. Starting a decade earlier typically cuts the required monthly contribution by more than half, because contributions made early have the most years to compound.
Several things materially affect real retirements and are not included here. Taxes on withdrawals are ignored, so a traditional 401(k) or IRA balance will produce less spendable income than the gross figure suggests. Required minimum distributions, which begin at age 73, force withdrawals whether you need the money or not. Healthcare costs before Medicare eligibility are excluded. Most importantly, sequence-of-returns risk is not modelled: a severe market decline in your first few retirement years does far more damage than the same average return spread evenly.
Because they are in today's purchasing power rather than future nominal dollars. This calculator subtracts inflation from your return before projecting, so the balance it shows is directly comparable to your current salary. Nominal projections look bigger and tell you less.
4% is the widely cited starting point, derived from research on 30-year retirements. Use a lower rate if you expect a longer retirement, want a bigger safety margin, or plan to leave money behind. Use a higher rate only if you accept a materially greater chance of depleting the portfolio.
Only as an input. Enter your expected annual Social Security benefit in the "other retirement income" field, in today's dollars, and the calculator treats it as income that reduces the amount your portfolio has to cover. It does not estimate your benefit for you.
No. Withdrawals from traditional 401(k) and IRA accounts are taxed as ordinary income, so the spendable amount will be lower than the gross balance suggests. Roth withdrawals are generally tax-free. Model a higher desired income, or a lower effective balance, to approximate the tax drag.
A large one. Because contributions compound, money invested in your twenties does more work than the same amount invested in your forties. In practice, starting a decade earlier often cuts the required monthly contribution by more than half to reach the same target.
Why did the math book look so sad?
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