Source:  Starbucks

By the time Starbucks (SBUX 0.65%) makes new information public, it is often the result of careful modeling and strategic planning that has been in the works for years. As Fools we love to try to speculate about the long-term future with the limited information we have, most of it in hindsight, without as much tangible insight into the future. Fortunately, management provides us with numbers that presumably came from its secret plotting.

Should we take management at its word?
You should probably never take the management of any company blindly at its word. Do your own homework as much as you can. However, that doesn't mean we should completely dismiss guidance figures either. Starbucks has racked up a long and successful history of delivering on forecasts and delivering results that are almost as delicious as its Frappuccinos so its credibility should carry some weight.

Back in March, Howard Schultz, CEO of Starbucks, told the public that he believed his company was "just getting started" and over the long term it is heading to an $100 billion market cap. It sounded ambitious with the $50-something billion current market cap at the time. But he obviously possesses a lot more information regarding the company's inner workings than we do.

It's all about earnings
Some argue that a company's cash flows determine its valuation. Others say it is by earnings. I say over the very long term cash flow and earnings should be similar anyway so why not just use earnings.

Source: Starbucks

In the short term with Starbucks you'll see that earnings exceed cash flows due to larger upfront cash payments for, perhaps, things such as new locations. Further out this should reverse, and you'll see cash flows that exceed earnings.

During a recent presentation, Scott Maw, CFO of Starbucks, gave some forward details about what the company expects in terms of numbers. He pointed out that global same-store sales growth has been between 6% and 8% for the last few years with earnings growth in a percentage range in the upper teens or low 20s. For this year, Starbucks expects another bump of between 20% and 22%.

Earnings per share for the previous fiscal year ending Sept. 23, 2013 were $2.26 per diluted share. Using the midpoint of 21% growth for 2014 would bring earnings per diluted share to $2.73. Maw and the company believe that based on all of the plans and "many layers of growth drivers" in place, over the long term Starbucks is targeting earnings-per-share growth of between 15% and 20% per year.

Show me da valuation
Using the midpoint of 17.5% in this case again and building up from the $2.73 per share guidance for this fiscal year ending in Sept. 2014, that multiplies out to a 90% increase in earnings for the fifth year from now ending in September 2018. That would put the earnings for that year at $5.20 per diluted share.

Starbucks has usually maintained a P/E ratio of between 25 and 30 over the last five years. For example, based on the current share price and EPS of $2.73 (for which the fiscal year is nearly over), that puts the P/E at around 28.

Source: Starbucks

Let's use the low end of the range or a 25 P/E on the $5.20 per share estimate. EPS of $5.20 times 25 equals $130 per share which just happens to be a hair shy of a $100 billion market cap. Coincidence? Perhaps Starbucks used logic similar to what I did here.

Foolish takeaway
If Starbucks meets its numbers guidance, the stock itself appears quite undervalued for the patient Fool who is looking for a steady long-term winner. There is even some speculative upside that Starbucks is guiding conservatively which it has done plenty of times in the past.