How can I calculate a percentage change ?

To calculate a percentage change, you can use this formula: (((y2- y1))/ y1) * 100. So, let's break this down with an example:

Suppose George owns stock in Vandelay Industries. His stock price went from $45 per share, to $47 per share. By what percentage has George's stock inceased ?

So George's stock has increased by 4.44 percent.