Every time a Dow stock splits, you have to adjust the so-called "divisor" — the number that's used to calculate the Dow Jones average. The current divisor is: 0.123017848, which means if you add up the 30 Dow stocks and divide by 0.123017848, you'll get the Dow Jones Industrial average. (For extra credit, you can calculate the divisor on your own, using the formula on Dow Jones Web site .)