Here's an online calculator:

http://www.marshu.com/articles/calcu...

Example: How to calculate percentage increase, Decrease or Difference How to calculate percent increase between two numbers? To calculate percent difference, you need to follow these steps:
1. Problem: You need to calculate percent % increase from 2 to 10
2. First Step: find the difference between two numbers, in this case, it's 10 - 2 = 8
3. Second: Take the difference, 8, and divide by the original number: 8/2 = 4
4. Lastly, multiply the number above by 100: 4*100 = 400%

In our case:

8.49 - 7.68 = 0.81

0.81 / 7.68 = 0.10546

0.10546 * 100 = 10.546% increase