I know what you're thinking. It's bad enough you have to figure out what you owe Uncle Sam every April; now you have to consider him in your retirement plans as well. Don't fret -- figuring taxes into your retirement investments doesn't require complex math or formulas. You just need some information. And that's exactly what I'm going to give you. Here are four things you should consider as you plan for your retirement.

1. Today's tax deductions will pop-up later. This may come as a surprise, but all the untaxed money that you keep pouring into your company's 401(k) retirement plan will eventually be taxed. When you cash out of your plan, you will pay taxes on money invested as well as all the gains and income your investments have generated over the years. So as you watch your retirement accounts grow, just remember that the bottom line on your statements does not include Uncle Sam's cut.

Some of you may be wondering why everyone keeps telling you to invest in tax-deferred plans. The idea is that you get to invest in your retirement and lower your current income bracket by the amount you contribute to the retirement plan. So now, when your income is rising or peaking, you get a tax break. Then when you're ready to receive your retirement funds -- and pay taxes on that money -- your tax bracket will drop significantly because you're no longer working full-time. So all the money you've invested gets taxed at a lower rate than it would have if you'd paid Uncle Sam along the way.