There's been a lot of controversy about your retirement number -- how much you need to save for retirement. Some argue that you need $1 million or even more in order to be comfortable, while others think that far less is necessary to be financially secure in your golden years. Yet there's really one fundamental thing you need to understand in coming up with the right answer for you.

In the following video, Dan Caplinger, The Motley Fool's director of investment planning, looks at this question and presents one simple truth: that it really depends on how you define what makes up a financially comfortable retirement. Dan notes that if you're looking for a bare subsistence lifestyle, you can get by on far less than the millions that many retirement experts urge you to save. But if you want to sustain or even improve your standard of living in retirement to take advantage of all the things you never had time to do in your career, then you will want to ensure you have a lot more savings to cover those costs. In the end, only you can decide which retirement number best fits your dreams.

Have general questions about Social Security? Email them to [email protected], and they might be the subject of a future video!