The Rent Review Specialist
Index-linked - CPI
The Consumer Price Index (CPI) is the official measure of inflation of consumer prices of the United Kingdom.
“The CPI calculates the average price increase as a percentage for a basket of 700 different goods and services. Around the middle of each month it collects information on prices of these commodities from 120,000 different retailing outlets. Note that unlike the RPI, the CPI takes the geometric mean of prices to aggregate items at the lowest levels, instead of the arithmetic mean. This means that the CPI will generally be lower than the RPI. The rationale is that this accounts for the fact that consumers will buy less of something if its price goes up, and more if its price goes down; it also ensures that if prices go up and then revert to the previous level, the CPI also reverts to its previous level (which is not the case with the calculation method used for the RPI). According to the ONS, this difference in averaging method is the largest contributing factor to the differences between the RPI and the CPI.” (Source: Wikipedia).
For the indices since 1988 and to calculate the CPI percentage change and apply the percentage to the rent for the adjusted figure, please visit CPI and Rent Calculator.