How to Find the Average Price of Common Stock

Most stock issued in the United States is common stock.

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Corporations can issue two types of stock: common stock and preferred stock. If you own common stock in a company, then you have a proportional ownership interest in that company. You do not have to buy all your common stock in a company at the same time but rather you can spread out your investment over a period of time. Since the purchase price of common stock typically changes every day due to market forces, common stock purchased at different points in time will cost different amounts of money. To determine the average value of your common stock, all you need is a couple basic pieces of information and a few simple calculations.

Step 1

Calculate the total amount of money spent on acquiring all your shares of common stock in a particular company. For example, if you bought 100 shares of common stock in Company X at $15 per share, 200 shares of common stock in Company X at $21 per share and 300 shares of common stock in Company X at $23, you would determine the total acquisition price of these shares as follows: [(100 x $15) + (200 x $21) + (300 x $23)] = ($1500 + $4200 + $6900) = $12,600.

Step 2

Add together the total number of shares of common stock you purchased in a particular company. Continuing with the same example, you would calculate the total number of shares as follows: (100 + 200 + 300) = 600 shares.

Step 3

Divide the number you got in Step 1 (the total cost of acquiring all your shares of stock in a particular company) by the number you got in Step 2 (the total number of shares of common stock your purchased in a particular company). Continuing with the same example, you would divide $12,600 by 600 shares to get $21 as the average price of common stock.