We'd all like to invest as successfully as the legendary Warren Buffett. He calculates return on invested capital (ROIC) to help determine whether a company has an economic moat -- the ability to earn returns on its money beyond that money's cost.

ROIC is perhaps the most important metric in value investing. By determining a company's ROIC, you can see how well it's using the cash you entrust to it, and whether it's actually creating value for you. Simply put, ROIC divides a company's operating profit by how the amount of investment it took to get that profit:

ROIC = Net operating profit after taxes / Invested capital

This one-size-fits-all calculation cuts out many of the legal accounting tricks (such as excessive debt) that managers use to boost earnings numbers, and provides you with an apples-to-apples way to evaluate businesses, even across industries. The higher the ROIC, the more efficiently the company uses capital.

Ultimately, we're looking for companies that can invest their money at rates that are higher than the cost of capital, which for most businesses lands between 8% and 12%. Ideally, we want to see ROIC greater than 12%, at minimum. We're also seeking a history of increasing returns, or at least steady returns, which indicate that the company's moat can withstand competitors' assaults.

Let's look at Microsoft (Nasdaq: MSFT) and two of its industry peers to see how efficiently they use capital. Here are the ROIC figures for each company over several time periods:

Company

TTM

1 year ago

3 years ago

5 years ago

Microsoft

75.8%

66.8%

72.2%

76.8%

Google (Nasdaq: GOOG)

59.5%

38.5%

43.8%

99.4%

Oracle (Nasdaq: ORCL)

23.2%

22.9%

22.4%

29.6%

Source: Capital IQ, a division of Standard & Poor's.  TTM = trailing 12 months.

Microsoft has consistently surpassed our 12% threshold for attractiveness and has kept its return on capital relatively steady over the past five years.  Google has also kept a high return on capital, but its ROIC has declined by almost 40 percentage points in the past five years; still, its up from three years ago.  After its initial decline from five years ago, Oracle has also maintained a fairly steady return on capital, but its returns appear to be much lower than others in the industry.  Nevertheless, the ROIC of this entire sector looks very attractive.

Businesses with consistently high ROIC are efficiently using capital. They can use their extra returns to buy back shares, further invest in their future success, or pay dividends to shareholders. (Warren Buffett especially likes that last part.)

To unearth more successful investments, dig a little deeper than the earnings headlines, and check up on your companies' ROIC.

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Jim Royal, Ph.D., owns shares of Microsoft. Google and Microsoft are Motley Fool Inside Value selections. Google is a Motley Fool Rule Breakers pick. Motley Fool Options has recommended a diagonal call position on Microsoft. The Fool owns shares of Google and Oracle. Try any of our Foolish newsletter services free for 30 days. The Motley Fool has a disclosure policy.