Background and Objective <p>The Dutch costing manual, part of the national guideline for economic evaluations, provides reference prices and standardized cost calculation methods to ensure transparency and comparability. Since its last update in 2015, new evidence, updated cost data, and user needs prompted an updated version to reflect current best practices and expand scope. The aim of this article is to present the update of the costing manual and the introduction of the web application facilitating regular updates.</p> Methods <p>The update of the costing manual followed a three-step approach. First, improvement needs were identified by user surveys and experts. Secondly, methodological guidance was revised using recent literature, national data sources, and expert input. Thirdly, the reference prices were updated. In parallel, a technical web application was developed and tested to facilitate ongoing digital access and regular updates.</p> Results <p>The updated costing manual consists of revised and updated references prices, including expanded intersectoral reference prices (e.g., education and justice). Clearer methodological guidance and improved transparency were established. Testing showed that the web-based application was intuitive to use and accurately reproduced reference prices consistent with the updated costing manual.</p> Conclusions <p>The costing manual was updated in line with the recent guidelines for economic evaluations. The manual is a comprehensive manual for use in costing studies for economic evaluations in healthcare from a societal perspective. The web-based application translated the costing manual into a practical digital tool, automating cost calculations and demonstrated usability, accuracy, and consistency with the manual.</p>