Staircases are one of the architectural history's oldest building elements and over the years they have transported humans comfortably and safely between different altitudes. By measuring the human stride length during the 1600s a formula could take place to facilitate the work in finding the best relationship between the step depth and step height. It was shown over the years that the formula did not always result in comfortable staircases. Therefore in 1957, Lars Einar Eriksson presented the so-called comfort curve, which is also a tool to facilitate the work of finding the best relationship between step depth and step height. The purpose of the study was therefore to verify whether these two tools still were two current tools or if these had to be adjusted. Furthermore, the aim for this study has been to find out what determines if a staircase is considered comfortable and safe for the user and if adjustments need to be made regarding the demands of the structures of the staircase. In order to achieve the objectives of the study and answer the research questions a questionnaire was developed and interviews were conducted on five of the largest staircase builders in Sweden. The study's conclusion can be answered through the issues; what is it that determines the comfort and safety of a staircase?, how can a staircase be made as comfortable as possible for as many people as possible?, Are the staircase formula and the comfort curve still relevant, or do they need to be adjusted? And are there any requirements in the Swedish regulatory framework that should be adjusted? The conclusion of what determines the comfort and safety of a staircase is partly individual, but at the same time it depends on several different factors that must be interconnected. In the end it is about a holistic assessment of the individual staircase. There are three factors that are fundamental to construct a staircase that is both comfortable and safe for as many people as possible. These factors are; Step depth, step height and step width. Further, it all comes down to analyze the stair environment and its users. The staircase formula does not necessarily need to be adjusted; it has shown to fulfill its purpose. It is instead about finding additional tools to the staircase formula when it in some cases does not provide comfortable stair conditions. Regarding the comfort curve, it turns out that many of the respondents in the study have not heard of it but still feels that it could be an additional tool to the staircase formula. The study has resulted in a developed area and an updated formula according to 4.1H + B = 1025 mm since the current stair formula does not cover the entire developed area. There should be made several adjustments regarding the demands of the staircase structures, particularly around the requirements for the description of the background, contrast marking, handrails and step height.