Our objective was to identify and assess freely available web-based cost-effectiveness calculators for health, well-being, and safety-promoting interventions. Several characteristics of such calculators could enhance or hinder the use of calculators in new contexts, yet they remain insufficiently studied.

We used a qualitative document analysis method with multi-channel web search strategy which explored 2100 websites, and 5 potential calculators suggested by content experts, resulting in the inclusion of 17 calculators in our study. Data was analyzed by deductive-inductive strategy that considered their applicability and, for example, their target groups, topic fields, usability-related characteristics, and scientific evidence base. The study was conducted applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

The characteristics of calculators were heterogenous, dependent on the context of their application and the target group of the calculator. Most calculators were clearly aimed at either employers, local public administrators, or policy makers. Cost-benefit analysis was the main method of analysis in 16 of the 17 calculators, and 12 of them included a comprehensive user manual. The scientific evidence base was explicated in 15 of the calculators, but the breadth of the evidence base varied widely between calculators.

A cost-effectiveness calculator’s contextual and practical applicability should be analyzed in addition to its scientific evidence base when considering its implementation.