Calculations have been a core part of business processes in several industries throughout the years. To streamline the process of calculations, companies seek to digitize their calculation tools to web-based calculation tools. There is currently a lack of studies regarding the performance of web-based calculation tools, and since technology changes occur rapidly, which leads to comparative studies becoming outdated, the availability of actual and relevant research regarding performance comparisons between web-development frameworks becomes imperative. The purpose of this study was to compare ASP.NET with Node.js Express performance-wise, while implemented as web-based calculation tools. The calculations implemented were placed in both the backend and frontend of ASP.NET and Node.js Express. This study consists of experimentation, presenting the experiment results, and analyzing the results to conclude the research questions of this study. The results showed that Node.js Express was the better framework performance-wise and the analysis explains why. This study also concluded that the backend was better performing than the frontend for calculations in ASP.NET, and that the frontend was better performing than the backend for calculations in Node.js Express.