Many Americans are worried they won’t have enough money to retire. As living costs rise, nearly one-third (30%) of Americans are not confident they will be able to cover day-to-day expenses for the remainder of their lives, and 63% of Americans believe the dream of retiring between the typical ages of 65 and 70 is unattainable, a recent TIAA survey found.

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However, money expert Ramit Sethi believes these fears are overblown. “What if everybody panicking about retirement is actually wrong? The truth is, you might retire with more than you think,” he said in a recent YouTube video.

He believes that if you actually do the math, you might be pleasantly surprised by your financial circumstances. Here’s the retirement math Sethi wants everyone to know about.

To figure out how much money you will actually need to retire, Sethi said to ask yourself three questions:

When do you want to retire?

How long are you going to live?

How much will you need each year?

If you don’t have the answers to the first two questions, Sethi said to assume a retirement age of 65 and that you’ll live 30 years in retirement.

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When it comes to answering the last question, Sethi noted that you will likely spend significantly less in retirement per year than you do during your working years.

“Retirement spending usually looks quite different,” Sethi said. “For many retirees, life often becomes simpler and less expensive.”

That’s because there are a number of expenses you no longer have to worry about, like commuting costs, work clothes and, ideally, mortgage payments.

Although Social Security likely won’t be able to cover all of your retirement costs, it can significantly offset the total amount you need in savings.

“If you made around the median salary of $62,000 … your Social Security check would be around $28,000 a year,” he said.

That amounts to roughly $2,300 a month, and the amount you receive increases each year with inflation.

If you want a rough estimate of what your total retirement savings goal should be, Sethi recommended using the 4% rule — divide your current salary by 4% to find your personal number. Using this calculation, if you made the median salary of $62,000, you would need roughly $1.5 million in retirement savings.

“That means if you have $1.5 million in your retirement account, then you can safely withdraw $62,000 a year,” Sethi explained. “To me, that’s revelatory. It tells me, I don’t need $5 million or $20 million. I need $1.5 million.”

Using the 4% rule, you will likely get a number that is more than you will actually need.

“Social Security will cover some of it,” Sethi said. “Maybe your spending will go down.”

He believes that if you start saving for retirement at 45 years old, you can still save enough to retire comfortably if you save $250 a month and ramp that up over time.

“I don’t think you guys realize how powerful compound interest really is,” Sethi said. “Even with that late start, by age 65, you could have hundreds of thousands of dollars saved.”

If you start earlier, it’s realistic to have a million dollars saved by retirement age.

“That’s a little over $37,000 a year you can safely withdraw using the 4% rule,” Sethi said. “Add in Social Security, which is about $26,500 a year — you’re looking at a more realistic retirement income with more than $60,000 you can spend every year.”

Another caveat to your retirement calculations is that you may not need as much money in retirement if you choose to live a simpler lifestyle.

“If you are more of a stay-close-to-home retiree, that probably means fewer flights, fewer hotel bills, maybe a paid-off house. So, let’s say you want $50,000 a year in retirement spending, using the 4% rule, that suggests you need approximately $1.25 million in investments,” Sethi said.

If, instead, you want to travel three months a year and are targeting $100,000 a year in spending, that means you’ll need a portfolio worth $2.5 million.

“Just remember, in both of these scenarios, you probably won’t need your portfolio to cover everything because you will have Social Security helping,” Sethi added.

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This article originally appeared on GOBankingRates.com: Ramit Sethi Reveals the Retirement Math Most Americans Get Wrong