The split ratio is an inverse of the number of shares that a holder of the stock would have after the split divided by the number of shares that the holder had before.

For example: Split ratio of .5 = 2 for 1 split

To determine a new stock price using the split ratio here is an example calculation:

Split Ratio = .5 Stock Price = $40 New Stock Price = $40/(1/split ratio)

New Stock Price = $20