Updated July 26, 2023
Indexation Formula (Table of Contents)
What is the Indexation Formula?
The term “indexation” refers to the technique of adjusting various values across a period of time based on the value in a particular year identified as the base year. In other words, the indexation techniques allow easier comparison of the changes in the value in any given year visàvis the base year.
The formula for indexation can be simply derived by dividing the value of any subject good in any given year by the value of the same good in the base year, and then the result is multiplied by 100.
Mathematically, it is represented as,
Examples of Indexation Formula (With Excel Template)
Let’s take an example to understand the calculation of Indexation in a better manner.
Indexation Formula – Example #1
Let us take the example of Crude Oil Price per barrel over the last five years as shown below:
 July 2014: $105.53
 July 2015: $50.56
 July 2016: $44.26
 July 2017: $52.48
 July 2018: $69.86
 July 2019: $60.43
Based on the abovegiven information, prepare the tables for the crude oil price index if the base year is 2014 and 2015.
Solution:
Crude Oil Price Index if Base Year July 2014
Price Index is calculated using the formula given below
Indexation = (Value in the Given Year / Value in the Base Year) * 100
For July 2015
 Price Index = ($50.56 / $105.53) * 100
 Price Index = 47.91
For July 2016
 Price Index = ($44.26 / $105.53) * 100
 Price Index = 41.94
For July 2017
 Price Index for= ($52.48 / $105.53) * 100
 Price Index for= 49.73
For July 2018
 Price Index = ($69.86 / $105.53) * 100
 Price Index = 66.20
For July 2019
 Price Index = ($60.43 / $105.53) * 100
 Price Index = 57.26
Crude Oil Price Index if Base Year July 2015
Price Index is calculated using the formula given below
Indexation = (Value in the Given Year / Value in the Base Year) * 100
For July 2016
 Price Index =($44.26 / $50.56) * 100
 Price Index = 87.54
For July 2017
 Price Index = ($52.48 / $50.56) * 100
 Price Index = 103.80
For July 2018
 Price Index = ($69.86 / $50.56) * 100
 Price Index = 138.17
For July 2019
 Price Index = ($60.43 / $50.56) * 100
 Price Index = 119.52
Therefore, the above two tables show the value of indexation changes with the change of the base year. Further, indexation makes the computation of inflation much easier.
Indexation Formula – Example #2
Let us take the example of a consumer price index (CPI) which is most the common form of indexation. Let us assume that the CPI basket of a country covers only four items, food, education, cloth, and fuel. The country has decided 2010 to be the base year for measuring CPI. Prepare the CPI for the following items.
Solution:
Calculation of Consumer Price Index (CPI)
Value of Consumer Price Index (CPI) Basket is calculated as
For 2010
 Value of CPI Basket = (25 * 40) + (30 * 32) + (20 * 56) + (15 * 35)
 Value of CPI Basket = 3,605
For 2015
 Value of CPI Basket = (25 * 36) + (30 * 35) + (20 * 45) + (15 * 40)
 Value of CPI Basket = 3,450
For 2019
 Value of CPI Basket = (25 * 41) + (30 * 37) + (20 * 50) + (15 * 38)
 Value of CPI Basket = 3,705
Consumer Price Index if Base Year is 2010
Consumer Price Index is calculated using the formula given below
Indexation = (Value in the Given Year / Value in the Base Year) * 100
For 2015
 Consumer Price Index = (3,450 / 3,605) * 100
 Consumer Price Index = 95.70
For 2019
 Consumer Price Index = (3,705 / 3,605) * 100
 Consumer Price Index = 102.77
Therefore, the CPI for the years 2015 and 2019 stood at 95.70 and 102.77, respectively.
Explanation
The formula for indexation can be calculated d by using the following steps:
Step 1: Firstly, identifying and fixing the base year is very important. The base year is selected by an authorized body based on various social and economic factors. Now, determine the value of the good or a basket of goods under consideration in the base year.
Step 2: Next, determine the value of the same good or basket of goods in any given year.
Step 3: Finally, the formula for indexation can be derived by dividing the value of any subject good in any given year (step 2) by the value of the same good in the base year (step 1), and then the result is multiplied by 100 as shown below.
Indexation = (Value in the Given Year / Value in the Base Year) * 100
Relevance and Uses of Indexation Formula
The concept of indexation is very important because organizations or governments usually use it to assess the impact of inflation on prices and asset values. Indexation finds application in wage comparison in a highinflation environment. Some common examples of indexation include consumer price index, raw material price index, consumer confidence index, business confidence index, etc.
Indexation Formula Calculator
You can use the following Indexation Formula Calculator
Value in the Given Year  
Value in the Base Year  
Indexation  
Indexation  = 


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Recommended Articles
This is a guide to Indexation Formula. Here we discuss how to calculate Indexation along with practical examples. We also provide an Indexation Formula calculator with a downloadable Excel template. You may also look at the following articles to learn more –