Planning for retirement is one of the hardest money issues people face, as the uncertainties of dealing with a goal that's years or even decades away are hard to navigate. In this edition of our Motley Fool Conversations series, Fool personal finance expert Dayana Yochim and retirement-planning analyst Dan Caplinger discuss retirement calculators and the ways that many people use them to try to find some answers to their questions of how much to save and how to invest.

Dayana notes how retirement calculators allow you to run any number of scenarios to help you plan your retirement. But as Dan points out, the to-the-penny answers that retirement calculators produce don't accurately reflect the bumpiness of real-life investing results, which inevitably include bumps and dips along the way.

The key to using retirement calculators well is to maintain the flexibility to deal with changing circumstances. Dan and Dayana bring up a number of areas where staying flexible can help, including how much money you spend from year to year, when you plan to retire, and how you invest. Taking advantage of opportunities to phase into retirement through part-time arrangements can give you extra income to help you bridge the gap to get more financial security.

Finally, Dayana and Dan discuss various investing ideas. Although many retirees have traditionally turned to bonds, stocks of companies that enjoy stable customer demand and pay healthy dividends are a good choice. Yet to provide long-term growth for retirees who expect to live 20 to 30 years beyond their retirement date, growth stocks can be appropriate even if they don't pay dividends. Dan names some stocks in both categories and concludes that the right balance will let you keep your bases covered.

Fool contributor Dan Caplinger and Fool personal finance expert Dayana Yochim have no position in any stocks mentioned. You can follow Dan on Twitter @DanCaplinger. The Motley Fool recommends Amazon.com and Kimberly-Clark. The Motley Fool owns shares of Amazon.com. 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.