Social Security will be the primary means of support for millions of workers after they retire. But it's especially critical for low-income workers, as Social Security can replace a huge portion of their pre-retirement income.

In the following video, Dan Caplinger, The Motley Fool's director of investment planning, goes through a typical situation for low-income workers. Using Social Security's benefits calculator, he notes that a 62-year-old worker making $15,000 a year can expect to replace between half and 85% of pre-tax earnings with Social Security benefits, depending on when the worker starts taking benefits. Dan runs through how Social Security calculates benefits, noting that the program is weighted toward giving low-income workers proportionally more of their pre-retirement income back. Dan concludes with comments about how the minimum wage controversy dovetails with Social Security, as Wal-Mart (NYSE:WMT) and Target (NYSE:TGT) as well as restaurant chains Yum! Brands (NYSE:YUM) and McDonald's (NYSE:MCD) deal with fallout over their wage policies.

Fool contributor Dan Caplinger has no position in any stocks mentioned. The Motley Fool recommends and owns shares of McDonald's. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.