What is percent change?
Percent change is the percentage difference you see from one value to another. For example, gas prices
increased about 10% from $3.15 to $3.45. The percentage is obtained by comparing the starting value
to the ending value using a fancy formula. We can use these to write objectives and to report changes
in programming!
EXAMPLES:
SMART Objective:
From June 2013 until June 2014, government officials in County Q will decrease rape myth acceptance as
indicated by a 33% increase from 66 to 88 on the Illinois Rape Myth Acceptance Scale.
In Program Reporting:
As a result of our outreach and awareness events, in this quarter we had a 52% increase in the number
of members in our Violence Prevention Coalition (from 23 to 35 members).
You could learn how to hand-calculate percent change but, unless you really love math, I would
recommend using a calculator. There is a great online option below, there is also a nice excel option
listed in the templates section of this website. (The major advantage to the excel option is that you can
get an ending value, not just the percent change).
What to keep in mind: percentage change works in TWO directions, so you could always have a percent
decrease or increase. Why? The calculator cannot tell by itself whether you want a percentage increase
or decrease. So, for example, if you put 66 as the starting value and ask for a 33% change (the default
listed above), you can see that a 33% increase from 66 is 87.78. In contrast, a 33% decrease is 44.22. It
is VERY important to think about whether you are looking to see an increase or decrease.
What might this look like in practice? Say your current budget is $66 for a project and you want to
decrease your budget by 33%. Then you would have an ending cost of about $44. In contrast, if you
have 66 participants in a youth prevention group and you want to increase participation 33%, then your
ending goal would be to have about 88 participants.
A nice way to make sure that you’re using a calculator correctly is to always do a common-sense check
after each calculation. If I am going from 13 to 15 and I get a result that says 323% increase, I might
think logically that the response seems sort of high. (In fact, a 100% increase would be double my
starting number of 13, or 26. 15 is less than 26 so my percentage should be under 100%). Sure enough,
323% this is the percent change from 13 to 55. When I put the correct numbers of 13 and 15 in the
calculator I can see the actual response, which is 15%. That makes a lot more sense!
To learn more and practice please refer to the other resources listed on this page.
Link to online percent change calculator:
http://www.percent-change.com/