This article is for investors who would like to improve their understanding of price to earnings ratios (P/E ratios). To keep it practical, we'll show how Bank of China Limited's (HKG:3988) P/E ratio could help you assess the value on offer. Bank of China has a P/E ratio of 4.59, based on the last twelve months. That means that at current prices, buyers pay HK$4.59 for every HK$1 in trailing yearly profits.

View our latest analysis for Bank of China

How Do I Calculate Bank of China's Price To Earnings Ratio?

The formula for P/E is:

Price to Earnings Ratio = Share Price (in reporting currency) ÷ Earnings per Share (EPS)

Or for Bank of China:

P/E of 4.59 = HK$2.80 (Note: this is the share price in the reporting currency, namely, CNY ) ÷ HK$0.61 (Based on the year to September 2019.)

Is A High P/E Ratio Good?

A higher P/E ratio implies that investors pay a higher price for the earning power of the business. That isn't necessarily good or bad, but a high P/E implies relatively high expectations of what a company can achieve in the future.

Does Bank of China Have A Relatively High Or Low P/E For Its Industry?

The P/E ratio indicates whether the market has higher or lower expectations of a company. We can see in the image below that the average P/E (5.7) for companies in the banks industry is higher than Bank of China's P/E.

Its relatively low P/E ratio indicates that Bank of China shareholders think it will struggle to do as well as other companies in its industry classification. Many investors like to buy stocks when the market is pessimistic about their prospects. If you consider the stock interesting, further research is recommended. For example, I often monitor director buying and selling.

How Growth Rates Impact P/E Ratios

P/E ratios primarily reflect market expectations around earnings growth rates. Earnings growth means that in the future the 'E' will be higher. Therefore, even if you pay a high multiple of earnings now, that multiple will become lower in the future. So while a stock may look expensive based on past earnings, it could be cheap based on future earnings.

Bank of China's earnings per share grew by -2.7% in the last twelve months. And it has improved its earnings per share by 2.0% per year over the last three years.

Don't Forget: The P/E Does Not Account For Debt or Bank Deposits

Don't forget that the P/E ratio considers market capitalization. That means it doesn't take debt or cash into account. Theoretically, a business can improve its earnings (and produce a lower P/E in the future) by investing in growth. That means taking on debt (or spending its cash).