Figuring out how much to save for retirement and when you can safely stop working can be difficult. A growing number of online retirement calculators, many of them free, are available to help. Although these calculators can yield vastly different results, they can still be useful tools.

Based on information about you and your finances, retirement calculators try to predict how much you need to save to achieve your retirement goals. There are many different types of calculators. Some are web-based while others require you to download a program or an app. The amount of information needed also varies from calculator to calculator.