In June 2003 the Reserve Bank published an inflation calculator ("the Calculator") on its website. This application enables interested users to calculate the effect of inflation on a "basket" of goods and services between two dates selected by the user. The Calculator has attracted significant attention, and well over 20,000 "hits" were recorded on the Calculator's home page during 2004. Links to the Calculator were established on a number of financial, educational and government websites, including Statistics New Zealand and the official New Zealand government historical site. This article documents an extension to the Calculator, enabling it to provide estimates of purchasing power back to 1862.