# How to calculate compound percentage change

1. Aug 26, 2010

### drdoug

Example: Inflation over time
Supposed that I want calculate the final percent change in a 10 year period.

(year , % Change) --> (1,3) (2,4) (3,7) (4,3) (5,2) (6,5) (7,4) (8,3) (9,4) (10,6)

How should I calculate the final percent inflation without having to calculate one by one?

2. Aug 27, 2010

### uart

100 ( 1.03 * 1.04 * 1.07 ... * 1.06 -1 )

3. Aug 28, 2010

### drdoug

sorry for my laziness but how would you calculate with negative values?

4. Aug 28, 2010

### uart

Each term in the above product is (1 + %change/100).

So for a 3% change (increase) the product term is 1.03, for a 3% decrease you would use 0.97 and so on.