Retirement planning doesn't have to be complicated. Sure, you could spend hours projecting your budget, estimating growth rates of your portfolio, and developing a retirement distribution strategy. But you can also save for a comfortable retirement without the excessive number-crunching. Start with these simple retirement planning tasks that you can complete in under 30 minutes.

1. Check your Social Security benefit estimates

You may already know that if you wait until your full retirement age (FRA) to file for Social Security, your benefit should be about 40% of your working income. But you can get to a much closer estimate by creating an account with my Social Security online. While you're at it, you can also find out what your FRA is. Those are two important pieces of information, and it'll only take you five minutes to find them.

Man sitting on the floor at home with laptop, taking notes.

Image source: Getty Images.

Navigate to my Social Security and set up a new account if you've never logged in before. Once you verify your identity and log in, you'll see your FRA and benefit estimates for different claiming ages. You can start receiving Social Security as early as age 62, but your benefit increases if you delay it. You qualify for your highest benefit at 70.

Your benefit estimates help you in two ways. First, the benefits available to you at fd should influence when you want to retire. If you think you'll be short on cash, for example, you might seriously consider waiting an extra year or two to retire.

Second, seeing your projected Social Security income can be a strong motivator to save. Those benefit numbers simply won't be high enough to fund your lifestyle on their own. But you don't have to take a major pay cut when you leave the workforce, as long as you get serious about saving now.

2. Set your retirement contributions

Next, you can log into your 401(k) and adjust what you're currently contributing to your workplace plan. This is also a five-minute task.

Generally, you should be saving 10% to 15% of your income if you are younger than 30. If you didn't start saving until after your 30th birthday, a higher contribution rate of 15% or more is a better starting point. And if you kicked off your savings plan even later (say, in your 40s), see if you can stretch to save 20% of your income.

Those savings percentages might feel pretty restrictive, if not impossible. But if you don't find a way to save now, you're facing a pretty serious lifestyle downgrade later. It might also help to know that a higher 401(k) contribution does lower your payroll taxes. That means your paycheck will not drop by the full amount of your contribution increase. For example, you might raise your contribution by $200 per paycheck, but your net pay may only decrease by $150 or $165, depending on your tax rates.

3. Learn the Rule of 110

The Rule of 110 gives you a quick guideline for how much in equities you should hold in your retirement account. Generally, holding higher percentages of equities gives you more growth potential, but also more risk and volatility. When you're young, you can invest for growth because you can handle more risk. If the market throws some volatility your way, you have the time to ride it out.

As you near retirement, you should gradually lower your risk. You'll also be lowering your growth potential, but that's a trade-off you can accept. At that point, you'd rather hold on to the money you have rather than risk losing some of it just as you're ready to retire.

You can learn the Rule of 110 in less than 60 seconds. It's an easy math problem: Subtract your age from 110. The result is the percentage of stocks you can safely hold given your age. At 30, it would be appropriate to hold 80% in equities and 20% in fixed income in your retirement portfolio. By age 50, though, you should lower your stock percentage to 60% and increase your fixed-income holdings to 40%.

Now take a look at the fund options available in your 401(k). You could implement the Rule of 110 with as few as two broad-based funds. A total U.S. stock market fund and a total bond market fund would do the job. You can get fancier than that with funds that give you exposure to different-size companies and different geographies. Just know that larger U.S. companies are less risky than smaller, international companies. Likewise, U.S. debt is lower risk than international debt.

And for next year

A year from now, you'll have some momentum in your retirement portfolio. If you're inspired, you can do some light number-crunching at that point. One next step to consider is using a compound-interest calculator to project your portfolio balance at retirement. But you also can't go wrong by focusing your energy on continuing to save. Your savings rate of 10% or more over the course of a few decades should put you in a great position to retire well.