Many workers say they are getting professional financial retirement savings advice, but few say they have taken a systematic approach to forecasting retirement savings needs.

About 50% say they came up with their estimates by guessing, according to researchers at the Transamerica Center for Retirement Studies, Los Angeles, a research center founded by a unit of AEGON N.V., The Hague, Netherlands.

Researchers commissioned a Web-based survey of 3,466 U.S. residents ages 18 and older who work either part-time or full-time for employers with 10 or more employees.

About 72% of the survey participants said they are investing for retirement, and about 32% of those participants – and 23% of all of the survey participants – said they are using professional financial advisors.

But only about 2% of the survey participants said they came up with their retirement savings need estimates by using figures supplied by financial advisors. Only 10% said they came up with their estimates by completing worksheets or doing other calculations.

When Transamerica researchers addressed the source of retirement needs estimates another way – by asking what services survey participants’ financial advisors provided – about 9% of all participants, and 39% of the participants with professional advisors, said their advisors helped them calculate their retirement savings goal.

About 32% of the survey participants who are investing for retirement said they had some kind of professional advisor, with 30% of investing participants at large employers saying they have advisors, and 35% of the investing participants at small employers saying they have advisors.

About 14% of the participants said they have saved less than $5,000 for retirement, and 24% said they have saved more than $100,000.