Rationale: In clinical and research settings, the validity and reliability of measurement instruments are crucial for reliable results. Current methods for computing validation metrics like Aiken's coefficients are often complex and error-prone, highlighting the need for a standardized computational tool to simplify and enhance this process. Aims and Objectives: The objective of this study was to develop AikenCalc, a tool created to automate the calculation of Aiken coefficients. This tool provides a quantitative method for examining the validity and reliability of consensus among expert judges. Method: AikenCalc was developed with Shiny app, an R library that allows an easy-to-use interface and improved computational efficiency. It was validated using a convergence method by comparing the manual calculations with those obtained using AikenCalc. Additionally, to examine usability and interface, six experts evaluated their experience using AikenCalc and provided improvement feedback. Results: AikenCalc demonstrated good convergent validity, closely aligning with the results obtained manually, and the six experts gave favorable ratings regarding the usability and interface of AikenCalc. Finally, it was shown that AikenCalc significantly reduced the time required for calculations, thanks to its user-friendly interface. Conclusion: AikenCalc represents a significant improvement in the validation of measurement instruments by automating and simplifying the calculation of Aiken's coefficients through a Shiny web application. Additionally, it fills a knowledge gap, as there is currently no similar calculator available in the field of research.