People use a lot of strategies to calculate how much they need for retirement, ranging from blind guessing to meticulously mapping out their expenses for a given year.

Some prefer to rely upon a benchmark, like the \$1.7 million that workers in Charles Schwab's 2022 401(k) Participant Survey estimated they'll need to cover their costs. But are any of those even right? Is there a right way to calculate retirement savings at all?

## How far will \$1.7 million go in retirement?

How far your nest egg goes in retirement depends on how quickly you're spending your money. That \$1.7 million might sound like a lot, but if you're spending \$500,000 a year, it's not going to get you very far. So rather than focusing on a specific savings figure, you need to think in terms of how much you're going to spend annually and how many years you expect your retirement to last.

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Everyone is going to have a different answer for this, but for this example, let's look at averages. The typical household headed by an adult 65 or older spent \$47,579 in 2020, according to the most recent Bureau of Labor Statistics Consumer Expenditure survey. Inflation has changed things since then. It's likely that many of these households are now spending more just to maintain the same lifestyle they're used to.

For simplicity's sake, let's say you spend about \$50,000 per year in retirement. Inflation will raise your cost of living over time. But your investments will also continue to grow, making it pretty likely that your savings will last several decades.

There's a 99% chance of a \$1.7 million nest egg lasting 30 years if you withdraw about \$50,000 per year and have 50% of your savings in stocks, 30% in bonds, and 20% in cash, according to the Vanguard Retirement Nest Egg Calculator.

But if you increase your annual withdrawals to \$100,000 per year, now there's only a 52% your nest egg lasts three decades. And if your retirement lasts longer than 30 years, that would also increase the risk that your savings would run out early.

## How to figure out how much you need for retirement

If you don't want to run out of money, you need a custom retirement plan. You can use figures like Schwab's \$1.7 million as a guide to see if you're in the ballpark, but you can't just assume this will be enough for you without doing some math.

Start by thinking about when you plan to retire and how long you expect to live. Consider your personal and family health histories, and don't be afraid to estimate a little high. Which is better: leaving an inheritance to your spouse or other heirs, or running out of money while you're still alive?

Think about how your spending might change between now and retirement as well. You won't have to divert funds to retirement savings once you're already retired, and you probably won't have to spend money on child care or daily commutation costs. But you might spend more on healthcare, travel, or your hobbies. Do your best to estimate your spending in each category, and again, leave yourself a little cushion.

From your monthly expenses, subtract money you expect from Social Security or a pension. You can create a my Social Security account to estimate how much you'll get from the program at various ages.

From there, you can enter your information into a retirement calculator to estimate how much you need to save each month and in total. Most will ask you to estimate your investment returns, and it's best to be conservative here. Use a 5% or 6% rate of return so your plan doesn't get derailed if your investments grow more slowly than you anticipated. If your money grows faster than expected, you can always move up your retirement date.

Once you have an idea of how much you ought to save per month, decide if it's feasible. If it is, set up automatic retirement contributions so you don't have to remember to make them. And if you can't afford to save as much as your plan suggests, consider delaying retirement a little while to give yourself extra time.