Saving for retirement isn't easy, but as costs continue to rise, it's more important than ever to have a robust nest egg.

Exactly how much you should save for retirement depends on a variety of factors, such as the cost of living in your area, how much you'll be receiving in Social Security benefits, and whether you plan to work in retirement. However, the average adult expects to need around $1.8 million to retire comfortably, according to a 2023 survey from Charles Schwab.

If you're looking to boost your savings with less effort, there's one simple rule that can help: Don't just save -- invest.

Person holding hundred-dollar bills against a blue background.

Image source: Getty Images.

Investing is far more powerful than saving

Many high-yield savings accounts earn interest rates of around 1% per year, with the highest-yielding accounts offering annual rates of around 4% to 5%. The stock market, on the other hand, has earned an average rate of return of around 10% per year, historically.

While that may not sound like a major difference, it adds up. If you have, say, $200 per month to contribute to your retirement fund, here's approximately how it would add up, depending on whether you're earning a 5% or 10% average annual return:

Number of Years Total Savings: 5% Average Annual Return Total Savings: 10% Average Annual Return
20 $79,000 $137,000
25 $115,000 $236,000
30 $159,000 $395,000
35 $217,000 $650,000
40 $290,000 $1,062,000

Data source: Author's calculations via investor.gov.

Investing can carry more risk in the short term, but over the long haul, you're far more likely to build a sustainable retirement fund than if you were to contribute to a savings account. So if you're looking to supercharge your savings, investing is one of the best ways to build a financially secure future.