Calculate percentage saved between two numbers?

Question

I have two numbers, the first, is the original price, the second, is the discounted price.

I need to work out what percentage a user saves if they purchase at the second price.

example 25, 10 = 60%   365, 165 = 55% 

What I dont know is the formula to calculate this.

Answer 1

I know this is fairly old but I figured this was as good as any to put this. I found a post from yahoo with a good explanation:

Let's say you have two numbers, 40 and 30.      30/40*100 = 75.   So 30 is 75% of 40.      40/30*100 = 133.    So 40 is 133% of 30.   The percentage increase from 30 to 40 is:     (40-30)/30 * 100 = 33%    The percentage decrease from 40 to 30 is:   (40-30)/40 * 100 = 25%.   These calculations hold true whatever your two numbers. 

Original Post

Answer 2

((list price - actual price) / (list price)) * 100% 

For example:

((25 - 10) / 25) * 100% = 60%