Enter the total purchase amount ($) and the number of shares owned into the Stock Average Cost Calculator. The calculator will evaluate and display the Stock Average Cost. 

Stock Average Cost Formula

The following formula is used to calculate the Stock Average Cost. 

  • Where SAC is the Stock Average Cost ($/share)
  • PA is the total purchase amount ($) 
  • #SO is the number of shares owned 

To calculate the stock average cost, divide the purchase amount by the number of shares.

How to Calculate Stock Average Cost?

The following example problems outline how to calculate Stock Average Cost.

Example Problem #1:

  1. First, determine the total purchase amount ($). The total purchase amount ($) is given as 8,000.
  2. Next, determine the number of shares owned. The number of shares owned is provided as 40.
  3. Finally, calculate the Stock Average Cost using the equation above: 

SAC = PA / #SO

The values given above are inserted into the equation below:

SAC = 8000 / 40 = 200 ($/share)


What is the significance of calculating the Stock Average Cost?

Calculating the Stock Average Cost helps investors understand the average price per share they have paid for their investments. This information is crucial for making informed decisions about selling or holding stocks, especially in determining the profitability of their investments.

Can the Stock Average Cost change over time?

Yes, the Stock Average Cost can change over time as additional shares are purchased at different prices. Each new purchase can alter the average cost per share, which is why it’s important to recalculate it after every transaction to keep track of investment costs accurately.

How does the Stock Average Cost affect tax calculations?

The Stock Average Cost can significantly impact tax calculations by affecting the calculated capital gains or losses when shares are sold. Using the average cost method to calculate the cost basis of sold shares can simplify tax reporting and potentially reduce taxable gains by spreading the cost over all shares owned.