Roughly 35% of Americans had no retirement savings as of January, according to a FinanceBuzz survey, and 2020 hasn't done them any favors. If you're one of this group, retiring a millionaire might sound like a pipe dream, but don't give up yet. It might be more doable than you think. Below, we'll look at how much you need to save to retire a millionaire and why you may not want to stop there.

How much do you need to save to retire a millionaire?

It's technically possible to retire a millionaire regardless of your current age or savings balance. But how probable it is depends on how much you can afford to save every month and how long you have until retirement.

Frustrated mature man sitting in front of laptop

Image source: Getty Images.

The good news is, you'll never have to save $1 million out of your paychecks as long as you're using a retirement account because you'll get a lot of money through investment earnings. However, the return you'll get -- and by extension, how much you need to save on your own -- depends on several factors.

The first is what you invest in. Some investments, like stocks, are known for offering larger potential returns but being more volatile while investments like bonds are considered more stable but generally offer smaller returns. You should invest in some of each, but know that your risk tolerance will change over time. You'll want to slowly move your money from riskier, but potentially more lucrative investments to more stable ones as you age to protect your growing nest egg.

To give you some idea of the difference your investment rate of return can make, consider a single $1,000 investment left to grow for 10 years. If it earns a 6% average annual rate of return, it would be worth $1,791 after a decade. But if it earned a 7% average annual rate of return, then it would be worth $1,967 -- a $176 difference. And this would be greater if we were talking about more money or more time.

Time itself plays a big part in how much your investments grow, which is why it's so important to begin saving for retirement as early as possible. If you wanted to save $1 million by the time you're 65, you'd only need to set aside about $405 per month if you started at 25 and earned a 7% average annual rate of return. But if you waited just five more years to start saving, you'd have to save about $585 per month to reach your goal, assuming the same average annual rate of return, because your investments wouldn't have as much time to grow in value.

Then there are your investment fees. Every retirement account has them, but they can vary widely depending on which plan you use and what you're invested in. Obviously, the more you're paying in fees, the less money you have to go toward your retirement. While you can't control all the fees associated with your account, you should aim to keep your investment fees under 1% of your assets annually if you can. Check your prospectus or check with your plan administrator if you're unsure how much you're currently paying.

You don't have to stop at $1 million

One million dollars sounds like a sufficiently impressive sum for retirement savings, and it will undoubtedly go a long way toward covering your expenses. But with an increasing number of retirees living into their 90s or beyond, it's possible that retirement could last 30 or more years for some people. In the meantime, inflation is driving up costs and the future of Social Security is uncertain. It won't disappear anytime soon, but it may not go as far in the future, placing an even larger savings burden on workers.

It's not unreasonable to think retirement could cost some people more than $1 million, especially for retirees who plan to travel or make big-ticket purchases in retirement. Those with serious health issues who require long-term care could also see their retirement costs rise significantly.

Rather than choosing an arbitrary savings goal like $1 million, take the time to calculate how much you believe you'll need for retirement based on your life expectancy, preferred retirement age, and estimated annual expenses in retirement. This will give you a better chance at saving enough to live comfortably for your full retirement, however long that might last.