How to Calculate a 3

Understand that stock splits do not give greater ownership in a company. Stock splits simply give you more shares of a stock while the value per share declines proportionately. Stock splits do create some tax advantages when stock is sold. Consult an accountant for professional advice.
Calculate a 3-for-1 stock split by knowing the number of shares you own prior to the effective date of the split. A stock split is merely a ratio: 3-for-1 means you now own three shares for every share previously owned. If you owned 1000 shares pre-split, you would now own 3000 shares post-split. The market value of your investment remains the same, however.
Calculate the new, adjusted earnings per share, cash flow per share, and other per share calculations by multiplying the pre-split amounts by 1/3. Know that at the time of a split announcement companies usually make pre- and post- balance sheets available.
Do not confuse a 3-for-1 stock split for a 1-for-3 split. This is also referred to as a reverse stock split. In a reverse stock split the value per share rises 3-fold and the outstanding number of shares declines by 2/3s. This technique is used for companies whose share price has dropped below margin.
Use the above technique for any ratio of stock split. Remember that the assets, liabilities and net worth stay the same. Only proportionate, per share amounts, change.