Have you ever wondered why stock investors keep talking about EPS all the time? I myself was confused at first until I understood just how important this metric is when choosing stocks worth buying.

EPS stands for earnings per share, meaning profit per share. It’s a way to see how much profit a company generates for each share it has issued. The formula isn’t complicated: just take net profit and divide it by the number of paid-up shares only.

Let’s look at a real example. In 2025, PTT had net profit of 90,166.37 million baht and paid-up shares of 28,562,996,390.9774 shares. When you calculate EPS, it comes out to approximately 3.15 baht—meaning each share generated 3.15 baht in profit for shareholders that year.

What many people overlook is that a high EPS doesn’t always mean the stock is good. A company can boost EPS by buying back its own shares, reducing the number of shares issued—this isn’t truly real profit.

This is where EPS growth comes in. It shows whether earnings per share are increasing or decreasing compared with the previous year. If EPS growth is positive, it indicates that the company is genuinely growing, not merely manipulating the numbers.

Another metric you should use alongside EPS is the PE ratio. This is calculated by dividing the stock price by EPS. A lower PE ratio means you’re getting a stock at a more reasonable price, but you should also compare it with the average of the same industry.

When analyzing stocks, I recommend looking at EPS across multiple years and watching the trend. It’s far better than only looking at EPS from a single year. You can check the data on the stock exchange’s website—EPS is usually found under the important financial results category.

Lastly, EPS is only one tool. Don’t use it alone to make investment decisions—you should also look at additional factors such as risk, the profit structure, and compare it with competing companies. If you do this, choosing your stocks will definitely be more rational.