This study estimates the cost of living in three cities – Florence, Bologna and Milan – in eighteenth-century northern Italy. Although they do not allow an understanding of the differences between social groups or seasonal consumption patterns, the calculation of living costs and the implied modelling have a twofold aim. First, they allow the calculation of real wages, which are obtained by dividing nominal wages by the cost of a consumption basket; therefore, broadly, they allow the Italian case to be put into great debates of economic history, such as the one on the Little Divergence between northern and southern Europe at the end of the early modern period. In this regard, we will show that the existing calculations used for this purpose have many criticalities, and we will solve them. Second, determining the cost of consumption baskets allows us to observe the role played by urban public institutions in mediating between the market and consumers, with relevant effects on price trends and, therefore, on the purchasing power of the urban population.