How to Calculate Fair Value for a Stock

Calculate the P/E ratio. The formula used to calculate the P/E ratio is 'current stock price per share' / ' current earnings per share.'
Compare the P/E ratio for your company with other companies in the same industry. For instance, if you want to find the fair value for a bank, you must compare the P/E ratio to other P/E ratios in the banking industry.
Interpret the meaning of the P/E ratio. A high P/E ratio means the company is overvalued and a low P/E ratio means the company is undervalued. For instance, if I own a company with a P/E ratio of 5 when the average P/E ratio for companies in the same industry is 3, I know that my stock is overvalued (expensive).
Adjust the stock price down to the average P/E ratio for the industry. If the average P/E ratio is 3, and the P/E ratio on my stock is 5 (current price $10 / earnings per share $2), then I can use the P/E equation to find what the stock price would need to be in order to have a P/E ratio of 3. The equation is: New P/E ratio x Earnings per share. The answer is 3 x $2 or $6. The fair market value for this stock is $6, not $10.