Quick: What’s the most important factor when it comes to saving for retirement? Is it picking the funds with the highest returns or lowest fees? Nope. How Much You Invest Makes a Huge Difference But it’s helped thousands of Baby Steps Millionaires build wealth, and it’ll get you where you want to go-to your retirement dream. It won’t make headlines or get you on the cover of a magazine. Here it is: Invest 15% of your gross income into tax-favored retirement accounts-like your 401(k) and IRA-every month. There’s a lot of bad advice out there when it comes to saving for retirement, and many people get overwhelmed by information when they’re finally ready to start investing.īut really, you just want to know what percent of your income you should save for retirement to be financially secure.