<p>Without further details, what I'd do is what you said. Take an 3/6/9/12-month average of the price index and calculate growth based on that.</p>

CC BY-SA 4.0
2019-08-01T07:49:55.160Z
2019-08-01T07:49:55.160Z
Art
<p>I have the monthly indexes taken from the National Institute of Statistics of my country (below), then I can calculate its inter-annual variation easily:</p>

<p>((index month year - index same month year - 1) / index same month year - 1) * 100</p>

<p>But my problem is that I want to compare this inter-annual variation against Financial Statements that show 3, 6, 9 and 12 months values. Then this inter-annual variation is useless because it shows the price variation only for a month and not for 3, 6, 9, 12 months period.</p>

<p>To solve this problem, should I calculate the cumulative inflation of 3, 6, 9 and 12 months of each year, then calculate de inter-annual variation of that cumulative inflation and finally be able to compare them to the Financial Statement inter-annual variation?</p>

<p>Is there any other way to do this more accurately ?</p>

<p><a href="https://i.sstatic.net/cC6Oo.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/cC6Oo.png" alt="enter image description here"></a></p>

<inflation>
How to calculate inter-annual variation of inflation for a 3 months period?
David_Rowie
# How to calculate inter-annual variation of inflation for a 3 months period?

(Asked by: username_0 on 2019-07-27)

I have the monthly indexes taken from the National Institute of Statistics of my country (below), then I can calculate its inter-annual variation easily:

((index month year - index same month year - 1) / index same month year - 1) \* 100

But my problem is that I want to compare this inter-annual variation against Financial Statements that show 3, 6, 9 and 12 months values. Then this inter-annual variation is useless because it shows the price variation only for a month and not for 3, 6, 9, 12 months period.

To solve this problem, should I calculate the cumulative inflation of 3, 6, 9 and 12 months of each year, then calculate de inter-annual variation of that cumulative inflation and finally be able to compare them to the Financial Statement inter-annual variation?

Is there any other way to do this more accurately ?

[![enter image description here](https://i.sstatic.net/cC6Oo.png)](https://i.sstatic.net/cC6Oo.png)

**Tags:** inflation

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## 1 answers

### Answer by username_1 on 2019-08-01. Score: 0

Without further details, what I'd do is what you said. Take an 3/6/9/12-month average of the price index and calculate growth based on that.


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