Measures inflation by charting the average change from month to month in the prices of goods and services purchased in the UK
The Retail Prices Index (RPI) is a key measure of inflation used by the Government. It uses a “basket” of goods and services to monitor how the cost of living is going up or going down annually.
In contrast to the other main measure of inflation, the consumer price index (CPI), RPI includes housing costs such as council tax and mortgage interest.
RPI is calculated using a “arithmetic mean” which basically means that RPI will always give a higher (or equal) figure than CPI, which is calculated using a “geometric mean