Many Americans worry that the money they've stashed away for retirement may not be enough to sustain them during their post-work years.

In fact, nearly 60% of retirees say they're very or somewhat concerned about running out of retirement savings, according to CNBC's August 2024 Your Money retirement survey conducted with SurveyMonkey.

That might be for good reason. A little over 20% of retirees surveyed say they have nothing set aside and 15% say they have less than $50,000 saved.

Since retirement can last 25 years or more after you stop working, worries about running out of money are understandable. Here's a look at the main obstacles preventing people from saving more for retirement and how to figure out how much you may need to accumulate.

Higher prices are causing people to save less for retirement

While Americans understand the importance of saving for retirement, many feel inflation is making it harder to do so effectively. Nearly 70% say they haven't been able to contribute as much as they would like to their retirement savings due to ongoing inflation, according to a survey from Allianz Life.

As of July, inflation has slowed to its lowest point since March 2021, down from a high of 9.1% in June 2022. But consumers are still feeling the effects.

"The rising cost of living is stretching American budgets," Kelly LaVigne, vice president of consumer insights at Allianz Life, said of the survey results. "Just because inflation has slowed doesn't mean prices have gone down."

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Housing costs in particular, which are typically a household's largest expense, have remained high, per the consumer price index, which measures how the price of various everyday goods and services changes over time.

In addition to higher costs, stagnant wages have made it harder for workers to set aside more money for retirement. Plus, nongovernment employers have steadily shifted away from pensions, which typically provide lifetime benefits in retirement, in favor of defined contribution plans like 401(k)s.

How to calculate how much money you'll need during retirement

It can be difficult to adequately save for retirement when you don't have a clear idea of how much you may need.

CNBC Make It's retirement calculator uses factors like your age, income and current retirement savings to give you an estimate of how much you should aim to put away by the time you retire.

And since saving for retirement is more of a marathon than a sprint, the calculator also explains how much you should aim to set aside each month and what your annual savings rate should be to reach that goal.

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