Ways to Select the Best 401K and Retirement Calculator

There are hundreds, if not thousands, of websites offering a 401(K) calculator or retirement calculator - all promising to show you exactly how much you need to save for your retirement.

However, do they actually work? And why do they all say something different? And with all these choices, which one is actually the best or right for you?

To compare the numerous 401(K) calculators out there, we inserted the same numbers, including savings rate, life expectancy and income into three various online and free calculators.

To do so, we inserted the same data about a pretend test subject - a 45-year old man with no spouse or dependents and an annual income of approximately $50,000.

Our subject had a minimal mortgage balance, a savings rate of about 10% and approximately $90,000 saved in a 401(K). He wanted to retire by the time he was 65, live on $50,000 (100% of his pre-retirement income) and he expected to live until the age of 100.

Keep reading to find out what each 401(K) calculator recommended and how they measured up.

The Ballpark Estimate Calculator (Online at: choosetosave.org/ballpark)

The Ballpark Estimate Calculator has some bad news - our test subject will have to save close to 56% of his annual salary to meet his goal of retiring by the time he's 65 with a 100% post-retirement income of $50,000. Prospects are grim for our test subject, unless he opts for riskier investments.

In terms of quality and experience, the site took a little over 9 minutes to complete the questionnaire and calculate the final results. Overall, it was easy to use and lets you include extra income sources like a part-time job or investment returns. The one major drawback is that you can't fiddle with the numbers or make major adjustments without starting over from the beginning.

Calculator: Nationwide's Retirability (URL: nationwide.com/nw/nrri/index.htm?wtgo=retirability)

Nationwide's Retirability calculator gives users what it calls an "R-Score," essentially scoring them on their retirement-readiness. A good score is anything above 100. Our poor test subject scored an 88.

The site took just under 8 minutes to input our information and come up with its results. One major feature of Nationwide's 401(K) tool is that it includes home equity as part of your assets. Considering that most Americans wind up tapping into that equity, it's more accurate.

The AARP Retirement Calculator (Online at: aarp.org/money/financial_planning/sessionseven/retirement_planning_calculator.html)

At the moment, our test subject is saving just over $400 in his retirement savings. According to the AARP calculator, that amount needs to increase to $1600 in order to meet his goal of full retirement at 65.

In terms of quality and ease, the AARP calculator was fast enough. It took about 10 minutes to complete. Though it wasn't bursting with features or fancy animations, it definitely produced results that were simple to read and easy to understand.