Determine a company's EPS for two accounting periods for which you want to measure a change. For example, use $1 for a company's EPS in one accounting period and $1.20 for the next.
Subtract the company's EPS in the older period from its EPS in the more current period. In the example, subtract $1 from $1.20 to get 20 cents.
Divide your result by the company's EPS in the older period. In the example, divide 20 cents by $1 to get 0.2.
Multiply your result by 100 to calculate the percentage change in EPS between the two periods. A positive result represents an increase, while a negative result represents a decrease. In the example, multiply 0.2 by 100 to get a 20 percent increase in the company's EPS.