You can find many financial tools online, including calculators that help you plan your retirement savings. How reliable are these calculators, and how much should you rely on them?

Most financial service providers offer their own calculators. A white paper released in late 2009 by the Pension Research Council (PRC) studied five of the most popular free calculators: those from AARP, Fidelity, MetLife, T. Rowe Price, and the U.S. Department of Labor... [288 word article, January 2010]