The aim of this study is to develop and test a methodology to calculate complexity levels of commercial streetscapes and compare whether those levels correspond to the ones perceived by users.An argument defended by the literature is that street facades are perceived as ordered when physical characteristics are structured according to some overall principle based on Gestalt Theory. In this study, complexity refers to a variety of elements and relationships in an aesthetic configuration, which is structured according to some overall principle based on this Theory. This concept is related to the level of order of elements that form an aesthetic composition; places where order does not exist are perceived and evaluated as chaotic and irregular, and not as complex. The perceived quality of a city is very much dependent on the visual quality of its streets, which depends on formal factors such as lengths of blocks, cross sections, widths of roadbeds and sidewalks, building setbacks and heights, frequencies of entrances to buildings, presence or absence of shop windows and shopfronts, and so on. In this study, formal factors are actually physical characteristics of commercial signs and buildings, such as silhouettes, facade details, facade articulation and colours.The method developed here to calculate the level of complexity in street facades was tested with samples from different cities and countries. Part of the sample was resident in Brazil and another part resident in England. The sample of 361 users comprised of different nationalities as the only pre-requisite to participate of the study was to be resident in the cities investigates – Pelotas and Gramado in Brazil and Oxford in England. Users from the following nationalities participated in the survey: Brazilian, British, Indian, Chinese, Mexican, Canadian, French, Italian, Portuguese, Thai, Brazilian/French, German, Greek, Iranian, Pakistani, Saudi, Taiwanese, Uruguayan, American, British/Brazilian, Danish, and Japanese. The results obtained from this sample reinforce the argument that even though user perception and evaluation of public spaces may be influenced by user background, user perception and evaluation of order is the result of an environment in which parts form the whole in such a way that redundancy, self-contradiction, and conflict are avoided.This study hopes that this method can be applied as a tool by urban designers and planners to identify, before a new insertion is built on, whether a new street intervention will increase or decrease people´s perception of visual quality since there is a relationship between the affective dimensions of “satisfaction” with complexity. In terms of the dimension of “satisfaction”, this relationship is directly proportional until an optimum is reached; when this limit is exceeded, the relationship becomes inversely proportional. Also, this method can be used to help reorganize street facades already perceived as negative by users.