Forty-six percent of Americans worry about not having enough for a comfortable retirement, according to a recent Gallup poll. The good news for working adults is that there's still time to turn things around. Here are four things you can do to give yourself the best chance of a happy retirement.

1. Plan out how much you'll need

Many Americans don't know how much retirement will cost, so it's understandable they would be anxious about it. The first step to any retirement savings plan is to figure out how much you'll need. Of course, this is impossible to predict with pinpoint accuracy because there are so many unknowns -- your life expectancy, the rate of return on your investments, the rate of inflation. But you can estimate how much you'll need.

Hand stacking coins in progressively taller piles

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The first step is to estimate your life expectancy. The average life expectancy in the U.S. is 78.7 years, but yours may be higher or lower than that. Look to your lifestyle habits and your family history to determine whether you should adjust this number up or down.

Then you need to determine your average living expenses in retirement. Bear in mind that inflation is probably going to continue eroding the value of the dollar, so you'll need more money now than you do today. A 3% annual inflation rate is a good estimate. So if you need $40,000 this year, you'll need $41,200 the next year and so on. If that all sounds complicated, you can use a retirement calculator.

Once you've determined how much you need for retirement, you can begin figuring out how to close the gap between where you are and where you want to be.

2. Up your contributions to your retirement accounts

This is an obvious one, but it bears repeating because it's so important. The more money you can spare right now, the more you'll have in retirement, and the sooner you start saving, the more compound interest can make it grow. You're allowed to contribute up to $5,500 to an IRA this year and $18,500 to a 401(k). Adults 50 and over can contribute up to $6,500 to an IRA and $24,500 to a 401(k).

If you max out your 401(k) this year, that $18,500 could grow into nearly $284,000 in 10 years, assuming an 8% rate of return. In 20 years, it will be worth $914,000, and in 30 years, over $2.3 million.

As this example shows, even a small contribution can make a big difference in the size of your nest egg. Look at how much you're currently contributing to your retirement accounts and see if you can afford to raise it, even if it's just by a single percent per paycheck. You may not even notice the extra coming out of your paycheck each month, but you'll notice the difference it makes in your retirement savings over time.

3. Open up a nonretirement investment account

If you've maxed out your 401(k) and your IRA for the year, that doesn't mean you're stuck with your savings account until next year. You can always open a nonretirement investment account as a supplement to your other retirement savings. Unlike with retirement accounts, any money you contribute to a nonretirement investment account will be taxed when you earn it and when you withdraw the money later. However, you'll still be better off than you would be if you left the money in savings.

The average savings account APY is a mere 0.08%. As I already mentioned, the average annual inflation rate is about 3%, so you're effectively losing money by leaving it in your savings. By contrast, you could earn 7% or more in interest every year with the right investments.

4. Boost your income

Increasing your income helps your retirement in two ways. First, it gives you extra cash, which you can use to contribute to your retirement funds. Second, it boosts your Social Security payments, which are calculated based on your average monthly income during the 35 highest-earning years of your life. Higher income today means larger Social Security checks tomorrow, so you won't need to rely on your personal retirement savings quite as much.

There are several ways you could increase your income. Try for promotions at work, consider switching careers to something more lucrative or pick up a side hustle to supplement your income from your regular job.

You may not be able to take advantage of all these tips, but even trying just one of them can help you to feel more confident in your retirement readiness. It may seem far down the road, but it comes up quickly, so the more prepared you can be today, the better.

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