Editors' pick: Originally published Dec. 13.

While socking money away in your 401(k) may sometimes seem like an endless journey to nowhere, some new numbers may put a smile on retirement savers' faces.

A new analysis showed 401(k) savers who have been in their company's plan for 15 years straight years showed the average account balance reached $331,200 at the end of the third quarter this year. That represents a 654% increase through returns and continued contributions from 2001, when savers had an average balance of about $43,900, according to the study Fidelity Investments.

"The potential power of the 401(k)s are huge if you take full advantage of the magic of compounding interest and free money in the form of profit sharing and company matches," said David Rae, a certified financial planner with Trilogy Financial in Los Angeles.

Rae said it's unlikely that type of growth is an outlier when you consider the 15 years in the study covered the "Great Recession," and other economic instability.

Joe Ready, head of Wells Fargo Institutional Retirement and Trust, said it is not hard for him to fathom that someone could have that type of growth. Average balances among active participants in 401(k) plans provided by Wells Fargo jumped from $56,000 in 2011 to $92,000 in 2016.

"That's just a five-year period - so if you were to triple that timeframe, assume a constant savings rate and factor in compounding growth, it is not far-fetched," he said.

Ready said the keys to making the most of a 401(k) plan, include starting early and taking advantage of your biggest asset, which is the power of time in terms of compounding and long-term market returns.

As well as making consistent contributions, he said savers should try to make that contribution 10% of pay, which can include employer match. He added one should resist the urge to tap the savings for loans or cashing out when changing jobs. It's also important to define an investment allocation strategy that aligns with one's goals - which can be modified accordingly as retirement nears.

"Saving for retirement in your 401(k) is a long-term proposition and can work when used appropriately; it's important to set a strategy with that in mind," Ready said.

Melinda Kibler, a certified financial planner and portfolio manager with Palisades Hudson Financial Group in Florida, said employees should remember they can make contributions of up to $18,000 in 2016, and for those over the age of 50, an additional $6,000 in catch-up contributions can be made. While employer match contributions are different from company to company, a common formula is to match 100% of employee contributions, up to 3% of the employee's salary.

"Employees should attempt to make a large enough 401(k) contribution to reap the benefits of a full company match," Kibler said. "Otherwise, employees are leaving free money on the table. If employees make meaningful annual contributions, combined with compounding investment growth, they will be well on their way towards a healthy retirement."

However, Kibler cautioned when investing a 401(k), employees should not set their expectations too high, as returns depends on a number of factors — including asset allocation, the specific investments selected and time frame. She added for investors who have the bulk of their investments in diversified equities, with some exposure to fixed-income, a goal of approximately 8% to 10% annualized return over the long-term is reasonable.

Nevertheless, while those numbers may seem significant, Rae reminds that is the money you will need to live off for your whole retirement, so more may need to be done.

"This big increase in 401(k) balances is a huge step in the right direction, but many American still have a ton of work to do preparing for retirement," he added. "Assuming a 5% withdrawal rate, $330,000 only generates around $1,375 per month before taxes. I don't know many people who can afford to live on that, even if they are getting Social Security."