Numbers can lie -- yet they're the best first step in determining whether a stock is a buy. In this series, we use some carefully chosen metrics to size up a stock's true value based on the following clues:

  • The current price multiples.
  • The consistency of past earnings and cash flow.
  • How much growth we can expect.

Let's see what those numbers can tell us about how expensive or cheap Wal-Mart (NYSE: WMT) might be.

The current price multiples
First, we'll look at most investors' favorite metric: the P/E ratio. It divides the company's share price by its earnings per share (EPS) -- the lower, the better.

Then we'll take things up a notch with a more advanced metric: enterprise value to unlevered free cash flow, which divides the company's enterprise value (basically, its market cap plus its debt, minus its cash) by its unlevered free cash flow (its free cash flow, adding back the interest payments on its debt). As with the P/E, the lower this number is, the better.

Analysts argue about which is more important -- earnings or cash flow. Who cares? A good buy ideally has low multiples on both.

Wal-Mart has a P/E ratio of 13.0 and an EV/FCF ratio of 20.9 over the trailing 12 months. If we stretch and compare current valuations with the five-year averages for earnings and free cash flow, we see that Wal-Mart has a P/E ratio of 14.0 and a five-year EV/FCF ratio of 21.3.

A positive one-year ratio of less than 10 for both metrics is ideal (at least in my opinion). For a five-year metric, less than 20 is ideal.

Wal-Mart has a mixed performance in hitting the ideal targets, but let's see how it stacks up against some of its competitors and industry mates. 

Company

1-Year P/E

1-Year EV/FCF

5-Year P/E

5-Year EV/FCF

Wal-Mart 13.0 20.9 14.0 21.3
Target (NYSE: TGT) 13.1 34.2 14.3 24.0
Costco Wholesale (Nasdaq: COST) 24.7 20.5 29.1 25.9
Best Buy NM 3.3 10.2 6.6

Source: S&P Capital IQ; NM = not meaningful because of losses.

Numerically, we've seen how Wal-Mart's valuation rates on both an absolute and relative basis. Next, let's examine ...

The consistency of past earnings and cash flow
An ideal company will be consistently strong in its earnings and cash-flow generation.

In the past five years, Wal-Mart's net income margin has ranged from 3.3% to 3.9%. In that same time frame, unlevered free cash flow margin has ranged from 1.9% to 3.8%.

How do those figures compare with those of the company's peers? See for yourself:

Wmt

Source: S&P Capital IQ; margin ranges are combined.

In addition, over the past five years, Wal-Mart has tallied up five years of positive earnings and five years of positive free cash flow.

Next, let's figure out ...

How much growth we can expect
Analysts tend to comically overstate their five-year growth estimates. If you accept them at face value, you will overpay for stocks. But even though you should definitely take the analysts' prognostications with a grain of salt, they can still provide a useful starting point when compared with similar numbers from a company's closest rivals.

Let's start by seeing what this company's done over the past five years. In that time period, Wal-Mart has put up past EPS growth rates of 9.2%. Meanwhile, Wall Street's analysts expect future growth rates of 10%.

Here's how Wal-Mart compares with its peers for trailing-five-year growth (because of losses, Best Buy's trailing growth rate isn't meaningful):

Wmt

Source: S&P Capital IQ; EPS growth shown.

And here's how it measures up with regard to the growth analysts expect over the next five years:

Wmt

Source: S&P Capital IQ; estimates for EPS growth.

The bottom line
The pile of numbers we've plowed through has shown us the price multiples that shares of Wal-Mart are trading at, the volatility of its operational performance, and what kind of growth profile it has -- both on an absolute and a relative basis.

The more consistent a company's performance has been and the more growth we can expect, the more we should be willing to pay. We've gone well beyond looking at a 13.0 P/E ratio. Its EV/FCF ratios are higher than its P/E ratios because capital expenditures outstrip depreciation. Still, its price multiples are in line with Target's and as a whole cheaper than Costco's (Best Buy is cheaper on all but one-year P/E, but it's less comparable to Wal-Mart and it has more uncertainty to deal with). Each of those three (Wal-Mart, Target, and Costco) has shown a consistent history of profitability and has built up great brand names in the retail space. Past and future growth for each is in the same ballpark as well.

As the numbers go, each looks reasonable, and it's a bit of a pick 'em in terms of which of the big discount retailers is best. As another data point, our CAPS community rates Wal-Mart four stars (out of five), Target four stars, and Costco five stars (out of five). But all this is just a start. If you find Wal-Mart's numbers or story compelling, don't stop here. Continue your due-diligence process until you're confident one way or the other. As a start, add it to My Watchlist to find all of our Foolish analysis.

In our brand-new free report, "The Stocks Only the Smartest Investors Are Buying," I wrote about a stock that's flying under the radar. I invite you to take a free copy to find out the name of the company I believe Warren Buffett would be interested in if he could still invest in small companies.