1 The RPI is calculated and published by the Office for National Statistics (ONS). The first RPI series above is calculated using a base value of 100.0 for the January 1974 RPI, while the second RPI series represents the same information, but calculated using a base value of 100.0 for the January 1987 RPI. The RPI data currently published by the ONS are based on the January 1987 re-basing.
2 The conversion factor between the two RPI series presented in this report is 3.945.
3 While the DMO does its utmost to ensure the accuracy of the data that appear on this page, the DMO is not the originator of RPI data. For definitive information on the RPI you should refer to the ONS.
4 Data are updated once a month on the day that the RPI from the previous month is published by the ONS.