6 ways to get rich without earning a six-figure salary

You don't have to earn six-figures to get rich.

As Robert Kiyosaki writes in his personal finance classic "Rich Dad Poor Dad," "Most people fail to realize that, in life, it's not how much money you make. It's how much money you keep."

By sticking to a few smart habits, almost anyone has what it takes to build wealth. Here are six strategies that could help you turn even a modest salary into millions.

Time is on your side when you're young. The sooner you start putting your money to work, the less you'll have to save each month to reach your goals, thanks to the power of compound interest.

If you start at age 23, for instance, you only have to save about $14 a day to be a millionaire by age 67. That's assuming a six percent average annual investment return.

If you start at age 35, on the other hand, you'd have to set aside $30 a day to reach seven figure status by age 67.

You can even build a multi-million dollar portfolio on a modest salary if you start young. Check out how much you have to save per paycheck to have $2 million stashed away by the time you're 67.

In just five years, Grant Sabatier went from having $2.26 in his bank account to $1 million. The 31-year-old self-made millionaire says "the single most important hack" he's used to build wealth is making daily deposits into his investment accounts.

He started with the goal of setting aside $50 a day. At first, "some days it was only $5," he says, "but I rarely missed a day."

His daily goal of $50 deposits soon became his daily minimum. He started setting aside "$70, then $80, then $100 dollars a day. … Then as my side hustles started really taking off I started depositing $500 plus a day … and the rest is history."

Today, Sabatier still makes a minimum daily deposit of $200.

Once you've committed to investing your money, the easiest way to stick with it over time is to make it automatic, meaning that you have money from your paycheck or checking account sent directly to your investment accounts every month before you even see it.

It worked for self-made millionaire Chris Reining, who crossed the $1 million threshold at age 35 and retired at 37. Automating your finances is "the one tiny habit that leads to wealth," he says.

Plus, it'll save you time and mental energy, he adds: "I automated my money years ago, and the benefit is I don't have to make decisions about where my money should go, how much I should invest, what I can spend, do I have enough savings and so on."

One Minneapolis-based millennial has already managed to bank $250,000 by age 28 and is on pace to retire comfortably by age 37. And he doesn't earn six figures. Part of the reason he's been able to save so much is by focusing on three specific expenses: housing, transportation and food. After all, as he points out on his blog, the average American spends 70 percent of their annual budget on these three expenses.

"If you can limit those expenses, that's where your big time savings will come," he tells CNBC Make It. But don't just up your savings rate — put your extra savings to work. As self-made millionaire Grant Cardone says, "Investing money is how you will get super rich. The only reason to save money is to one day invest money."

Self-made millionaires agree: If you want to make big money, you can't be content with only one source of revenue. "You won't get rich without multiple flows of income," says Cardone, who was deep in debt before reaching seven figures.

Developing multiple streams of income could mean starting a side hustle, generating passive income or picking up a high-paying side job.

Need inspiration? Check out how one millennial turned $200 into $1 million by selling Kevlar pants online and how Daymond John built a billion-dollar brand while living on the tips he made waiting tables at Red Lobster.

If you want to build wealth, you have to have a clear goal, specific plan and hard deadlines.

Cardone recommends crunching the numbers to see what it actually takes to reach seven-figures, or whatever your personal goal is. He writes in "The Millionaire Booklet: How To Get Super Rich," "For any goal to be achievable, you must believe in its possibility as a realistic and doable goal. The way to do this is simply by doing Million Dollar Math. How many different ways can you collect $1 million?"

If you can figure out a way to get 5,000 people to buy a $200 product, you'd have $1 million, says Cardone. Or, if 5,000 people paid you $17 a month for 12 months, that would also get you to $1 million. Of course, these examples are highly simplified, but the point still stands: "Do the math to create possibility, then create strategy," says the self-made millionaire.

This is an update of a previously published story.

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