Definition of earnings: The annual profits of a company after deduction of tax, dividends to preference shareholders, and payments to bondholders. The figure for earnings is in a company's P&L.
The ratios used in connections with earnings are:
The number of shares in issue can be found in the balance sheet, and it will usually also state the average number of shares in issue during the year.
The P/E tells you how many years you would have to wait to get your money back on your investment.
But how meaningful is this? There is an argument that the P/E is a flawed concept because whilst EPS is based on historical data (actual earnings figures) the current market price of a share is based on future expectations. And since future expectations are only partly determined by past performance the logic of a connection between them is tenuous.
In determining whether a P/E is 'high' or 'low', compare it with the P/E for other companies in the same sector.
The important thing about the PEG is that both the earnings and the EPS growth are based on brokers' estimates for the next 12 months. i.e. they are comparing like with like. The PEG rule of thumb is that a company with a PEG of less than one is a bargain.