Savings & Retirement
Published on September 13, 2025
Start from the income you want, not the pot. Divide your desired annual income by the withdrawal rate you consider safe. Wanting $50,000 a year at a 4% withdrawal rate implies a corpus of $50,000 / 0.04 = $1,250,000. At a more cautious 3.5%, the same income needs $1,428,571.
Published by PraxisCalc, a Zeta Digilux Labs project
The idea of retirement is enticing: a time to relax, travel, and pursue hobbies. But behind this dream is a critical question that causes anxiety for many: "How much money do I actually need to save?" The answer is your "retirement corpus", the total sum of money that will fund your post-work life.
Your retirement corpus is the total capital you need to accumulate by the time you retire. This fund must be large enough to generate sufficient income to cover your living expenses for the rest of your life, while also accounting for the erosive effects of inflation.
Calculating this number isn't simple guesswork. It depends on several key variables:
Stop wondering and start planning. Our Retirement Calculator takes all these complex factors into account to give you a clear savings target and the monthly investment needed to get there.
Use the Retirement Calculator →While our calculator provides a detailed analysis, a common rule of thumb is the 4% Rule. This suggests you can safely withdraw 4% of your total retirement corpus in your first year of retirement, and then adjust that amount for inflation each subsequent year, without a high risk of running out of money.
To use this, you first need to estimate your annual expenses in your first year of retirement. For example, if you need $80,000 per year, your target corpus would be:
Corpus = Annual Expenses / 0.04Corpus = $80,000 / 0.04 = $2,000,000
This is a good starting point, but a comprehensive calculator will provide a much more personalized and accurate target.
Your retirement corpus target doesn't need to cover 100% of your retirement expenses on its own. For U.S. savers, Social Security typically replaces a meaningful portion of pre-retirement income, the exact amount depends on your earnings history and the age you claim benefits, anywhere from 62 (reduced benefit) to 70 (maximum benefit). A common planning approach is to estimate your expected Social Security benefit first, subtract it from your projected annual expenses, and then use the remainder as the annual withdrawal figure when back-solving for your corpus target with the Retirement Corpus Calculator.
Employer-sponsored plans like a 401(k) are usually the most tax-efficient place to build that corpus, especially up to any employer matching contribution, which is effectively an immediate return on your savings. IRAs (Traditional or Roth) are a common next step once the employer match is captured, since they often offer a wider range of investment choices than a workplace plan.
The order in which investment returns occur matters enormously in the years right before and after retirement, even if the average return over the full period is identical. A market downturn in the first few years of retirement, combined with ongoing withdrawals, can permanently damage a portfolio's ability to recover, because withdrawals during a down market lock in losses on shares that are sold at depressed prices. This is why many retirement plans shift toward a more conservative asset allocation in the five to ten years before retirement, and why some retirees keep one to two years of expenses in cash or short-term bonds specifically to avoid selling equities during a downturn.
The widely cited "4% rule" suggests withdrawing 4% of your retirement corpus in the first year, then adjusting that dollar amount for inflation each subsequent year, based on historical research into how often that approach avoided running out of money over a 30-year retirement. It is a useful starting reference point, not a guarantee, since it was derived from historical US market returns that may not repeat exactly, and it doesn't account for unusually long retirements or unusually poor early returns. Many planners now treat 3.5%-4% as a reasonable planning range and recommend revisiting the withdrawal rate periodically based on actual portfolio performance rather than following the original percentage rigidly for three decades.
Calculating your retirement corpus is the most important first step in planning for your future. Once you have a clear target, you can break it down into a manageable monthly savings goal. The earlier you start, the more the power of compounding can work in your favor, making it easier to reach your goal and enjoy a comfortable, stress-free retirement. For official guidance on this topic, see the Social Security Administration's retirement guidance.
Divide the annual income you want by your withdrawal rate as a decimal. $50,000 / 0.04 = $1,250,000. This is sometimes stated as the 25x rule, since dividing by 4% is the same as multiplying by 25.
A guideline that a diversified portfolio can support withdrawals of about 4% of its starting value in the first year, rising with inflation after that, with a reasonable chance of lasting 30 years. It is a planning benchmark drawn from historical returns, not a guarantee.
A large one. Moving from 4% to 3.5% raises the target for $50,000 of income from $1,250,000 to $1,428,571, an extra $178,571. Small changes to this assumption move the target more than most changes to your savings rate.
Yes. Deduct any guaranteed income first and size the corpus against the shortfall. If a pension covers $20,000 of a $50,000 target, you only need to fund $30,000, which at 4% is $750,000 rather than $1,250,000.
The 4% rule already assumes withdrawals rise with inflation, so the corpus figure is in today's money. What inflation changes is the nominal amount you will actually be spending decades from now, which is why the target should be revisited periodically.
A longer retirement needs a lower withdrawal rate. Someone retiring at 45 rather than 65 is funding perhaps 45 years instead of 25, and many planners drop to 3% or 3.25%, which raises the corpus for $50,000 of income to well over $1,500,000.
For faster estimates, open the retirement calculator and test the numbers with your own assumptions.
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