Doing retirement planning is challenging because you have to figure out how much income you'll earn from your savings. But how can you make a good estimate?

In the following video from our Retirement Q&A series, Dan Caplinger, The Motley Fool's director of investment planning, answers a question from Fool reader Rick about how to figure out what your retirement income will be. Dan notes that the usual rule is that you can take 4% of your retirement nest egg each year, pointing out that it doesn't necessarily have to be "income" but rather can come from spending down principal. But Dan points out that this calculation doesn't include Social Security, employee pensions, or other sources of regular monthly income beyond your investments. To come up with the right figure, you have to add in all your income sources, but when you do, you'll have a good sense of what you can expect to spend by using the 4% rule.

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