Instead, go to the retirement calculator at ChooseToSave.org and crunch your numbers.

The retirement calculator at FinancialEngines.com, which costs $150 to use for a full year, helps solve that problem.

You can also search for retirement calculators online; www.dinkytown.com, www.choosetosave.org/ballpark or www.fool.com are good places to start.

He faults typical retirement calculators for overly simplifying the process.

I especially like online retirement calculators that help determine how much to invest during your working years.

For more complicated situations, there are several online retirement calculators on the Internet.

Some retirement calculators, appropriate for safe investments, assume a constant, unvarying rate of return.

The assumptions keyed into a retirement calculator are critical.

The graph above can be compared with those generated by many retirement calculators.

Also take advantage of tools such as retirement calculators that can be found online.