A lot of Americans are counting on Social Security benefits when they retire, but many don't know how much they can expect to receive.

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But that's no longer the case thanks to a new online tool by the Social Security Administration that allows people to find out how much they can expect in Social Security benefits when it's time to say goodbye to the working world.

People can track their future retirement benefits by creating an account at www.socialsecurity.gov/my account. Once there, the website will prompt you to create a personal account with a secure username and password.

"So far we have about 13.5 million people currently using 'my Social Security' accounts, and we're getting a new sign up every six seconds," said Mark Hinkle, deputy press officer for the Social Security Administration.

Once an account is open, people can review and verify their lifetime earnings for accuracy.

"It's good to get that information as early on as possible, as young as possible, because they can actually plan and have a comfortable retirement with the knowledge of what they are going to get from Social Security," Hinkle said.

The website also allows users to manage their benefits once they start to receive them.

On average, Social Security replaces about 40 percent of their pre-retirement earnings.  "It's obviously one part of a solid retirement and having an estimate is a good starting point for what you need to do to supplement Social Security and plan for your retirement.