No one can say millennials aren't optimistic.

Even with the uncertainty that surrounds stock markets today, millennials think retiring by age 61 remains a realistic possibility, according to a new Bankrate survey. However, older generations are not as confident as the youth of America. Half of the baby boomer population thinks it's best to retire by age 65 or older, for example.

But just how feasible is it for millennials to retire in their early 60s? It won't be easy, but retirement planning experts weighed in on how they can reach that lofty goal. 

Start Saving Early

Millennials who are just beginning to earn an income or who still might be in college probably don't think saving for retirement should be a big priority when they're just starting out. That's the wrong mentality to have, said Chris Dixon, managing partner with Oxford Advisory Group. Dixon advocates for millennials to develop a plan of action early because even a five-year delay in saving can cause a huge impact on their accumulated wealth down the road.

"If a 27 year old puts away $3,600 annually into a Roth IRA earning 7% annually, at age 61 they would have over $664,705," said Eric Kearney, an advisor at Retirement Wealth. "By procrastinating and waiting until age 30, that number goes down to $393,185. If they wait until age 40, it's only worth $172,821."

Be Proactive in Your Retirement Planning

Echoing the same reasoning behind why people should diversify their investment portfolio, millennials should have multiple different savings vehicles in their retirement portfolio, according to experts.

A big mistake millennials can make when it comes to saving for retirement is relying too heavily on just one or two types of savings accounts, said Jadon Newman, CEO of Noble Capital. Allocating money to different assets can mitigate losses from market volatility and can help millennials grow their nest egg so they actually could retire by 61 if they want.

"We would recommend setting up an IRA, 401k or a Roth IRA," Dixon said in an email. "All of these have tax preferential treatment, which means your money can grow without a tax burden. Money can be invested in mutual funds, stocks that produce dividends and Index Universal Life contracts."

Take some risks

One advantage millennials have over older generations when it comes to saving is youth. Their investment horizons are longer, which means they can afford to handle some volatility when it comes to investing, Brad Geddes, a financial planner at Decker Retirement Planning, said in an email. Having a little money in assets that may yield some high returns can put millennials in a better position to retire early.

"When you're young, it makes sense to have a good percentage of higher-risk, higher-return investments like stocks in your portfolio because you need to accumulate more money, but you still have time to recover if the stock market takes a dive," Newman said.

More from Personal Finance

How to Take an Early Retirement in 8 Steps

How to Take an Early Retirement in 8 Steps

What Is Litecoin? What to Know in 2019

What Is Litecoin? What to Know in 2019

Is General Electric Stock Still Good for Your Retirement Account?

Is General Electric Stock Still Good for Your Retirement Account?

This Is How Hot It's Going to Get Where You Live

This Is How Hot It's Going to Get Where You Live

What Is a Timeshare and Is It a Financial Risk in 2019?

What Is a Timeshare and Is It a Financial Risk in 2019?