'Simple rules of thumb like 10-times-the-annual-income are a good way for people to quickly gauge their situation,' Jean C. The experts at Lincoln added that we should also get advice from a financial professional, enroll in an IRA or some other retirement fund, have an investment strategy and save more in good years.

'The 10x assets-to-income ratio is a guide that can help people determine how they can be better prepared for retirement,' said Chuck Cornelio, president of Defined Contribution at Lincoln Financial Group. The respondents didn't rely on receiving an inheritance or selling their home or business, or on redeeming shares of their old company's stock, the study said.

Lincoln arrived at its magic number by surveying 1,200 retirees of varying means. If your income dips to $50,000, then readjust to $500,000. If you're making $60,000 a year in salary, dividends and anything else, you should aim for 10 times $60,000, or $600,000 in assets by the time you retire. The desired amount will shift depending on what we're making throughout our working life, but the 10x benchmark always applies. It says we need to have 10 times our annual income for retirement. We're not there yet, but a new study by Lincoln Financial Group ( LNC) is getting closer. Wouldn't it be great if you could plot your retirement with a single, simple mathematical equation? Imagine plugging in the numbers and, presto, you know precisely what it will take to make your golden years gleam.

What is the 10x rule