Abstract: Embodiments of the present invention relate to a method for converting a database of point address data into a database of address range data using a computer, wherein each point address comprises an address number, a street name and a geographical location. The method comprises assigning each point address to a chain based upon its street name; ordering the point addresses in each chain according to their geographical location; determining the direction and range of the road numbers in at least part of at least one chain; and storing the direction and range data as address range data.