Because reinvested dividends take the form of additional shares of stock, the formula is easy to calculate. The total value is equal to the stock price multiplied by the total number of shares, including any shares purchased through dividend reinvestment.
Let’s say an investor owns 100 shares of Company XYZ and received a .50 cent per share quarterly dividend. They would have "earned" $50 (100 x .50) to reinvest. Assuming that using dollar cost averaging, the company’s share price was $25 the investor purchased two additional shares. The investor's total return is now 102 x (share price).