Courtesy : Investopedia.
By definition, EPS is net income divided by the number of shares outstanding, however, both the numerator and denominator can change depending on how you define "earnings" and "shares outstanding." There are numerous ways to define earnings, so let's start with shares outstanding.
Shares Outstanding
Shares outstanding can be classified as either primary, or basic, (primary EPS) or fully diluted (diluted EPS). Primary EPS is calculated using the number of shares that have been issued and held by investors. These are the shares that are currently in the market and can be traded.
Diluted EPS entails a complex calculation that determines how many shares would be outstanding if all exercisable warrants, options, etc. were converted into shares at a point in time, generally the end of a quarter. Diluted EPS is preferred, because it is a more conservative number that calculates EPS, as if all possible shares were issued and outstanding. The number of diluted shares can change as share prices fluctuate (as options fall into/out of the money), but generally the Street assumes the number is fixed as stated in the 10-Q or 10-K.
There are five types of EPS to be defined in the context of the type of "earnings" being used.
Reported EPS (or GAAP EPS)
We define reported EPS as the number derived from generally accepted accounting principles (GAAP), which are reported in SEC filings. The company derives these earnings according to the accounting guidelines used. A company's reported earnings can be distorted by GAAP. For example, a one-time gain from the sale of machinery or a subsidiary could be considered as operating income under GAAP and cause EPS to spike. Also, a company could classify a large lump of normal operating expenses as an "unusual charge," which can boost EPS because the "unusual charge" is excluded from calculations. Investors need to read the footnotes in order to decide what factors should be included in "normal" earnings and make adjustments in their own calculations.
Ongoing EPS
Ongoing EPS is calculated based upon normalized, or ongoing, net income and excludes anything that is an unusual one-time event. The goal is to find the stream of earnings from core operations, which can be used to forecast future EPS. This can mean excluding a large one-time gain from the sale of equipment, as well as an unusual expense. Attempts to determine an EPS using this methodology is also called "pro forma" EPS.
Pro Forma EPS
The words "pro forma" indicate that assumptions were used to derive whatever number is being discussed. Different from reported EPS, pro forma EPS generally excludes some expenses or income that were used in calculating reported earnings. For example, if a company sells a large division, it could, in reporting historical results, exclude the expenses and revenues associated with that unit. This allows for more of an "apples-to-apples" comparison.
Headline EPS
The headline EPS is the EPS number that is highlighted in the company's press release and picked up in the media. Sometimes it is the pro forma number, but it could also be an EPS number that has been calculated by the analyst or pundit that is discussing the company. Generally, sound bites do not provide enough information to determine which EPS number is being used.
Cash EPS
Cash EPS is operating cash flow (not EBITDA) divided by diluted shares outstanding. Generally, cash EPS is more important than other EPS numbers, because it is a "purer" number. Cash EPS is better because operating cash flow cannot be manipulated as easily as net income and represents real cash earned, calculated by including changes in key asset categories, such as receivables and inventories. For example, a company with reported EPS of 50 cents and cash EPS of $1 is preferable to a firm with reported EPS of $1 and cash EPS of 50 cents. Although there are many factors to consider in evaluating these two hypothetical stocks, the company with cash is generally in better financial shape.
The bottom line
There are many types of EPS being used and investors need to know what the EPS numbers they see represent and determine whether they are a good representation of a company's earnings. A stock may look like a great value because it has a low P/E, but that ratio may be based on assumptions which, upon further research, you might not agree with.
