Unexpectedly Intriguing!
March 12, 2008

What is the total percentage change between an old figure and a new one? And for that matter, what is the average rate of change over the time between when the old and new values were recorded?

These are questions that we answer all the time, so we were somewhat gobsmacked to realize that we had never gotten around to posting a tool that anyone can use to answer the same questions for themselves. So, we're getting around to it today!

The data you'll need to enter in the tool below is really straightforward: you just need to enter an older (or starting) value, a newer (or ending) value, and enter the amount of time that elapsed between when these figures were noted. Our tool will find the total percentage change between the older and newer values and will also find the compound annual growth rate (CAGR) that corresponds with the time interval and values that you enter.

That's it! Here's the tool:

Value Data
Input Data Values
Older or Starting Value
Newer or Ending Value
Time Data
Number of Elapsed Years
Number of Elapsed Months
Number of Elapsed Days

Total Percentage Change and Annualized Growth Rate
Estimated Results Values
Total Percentage Change Over Elapsed Time [%]
Annualized Rate of Change [%]

In the calculations for the tool above, the total elapsed time is found by adding each of the entries for elapsed years, months and days. We figure that feature makes this particular tool slightly easier to use with time periods you're much more likely to know than what some similar tools that you might find elsewhere on the web require.

Looking at what we do, we find we do this kind of math all the time for all kinds of things, such as finding out how big an increase in a budget line item, taxes, GDP, investment value or other personal finance stuff is compared a previous level or to find out what the annualized rate of change in a value between two points in time might be.

Like we said at the beginning - we were surprised to find we hadn't done it already!


About Political Calculations

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Welcome to the blogosphere's toolchest! Here, unlike other blogs dedicated to analyzing current events, we create easy-to-use, simple tools to do the math related to them so you can get in on the action too! If you would like to learn more about these tools, or if you would like to contribute ideas to develop for this blog, please e-mail us at:

ironman at politicalcalculations.com

Thanks in advance!

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