To enable evidence based and informed policy and investment decision for extension and advisory systems, the EAS-Yardstick (EAS-Y) has been developed through a consultative expert process. It constitutes a holistic scoring tool based on a comprehensive set of metrics that can capture all the nuances of the pluralistic EAS. Metrics are organized into two modules, related to EAS performance and to EAS outcomes, each subdivided into key EAS topics. These cover elements of the EAS enabling environment, scope and provision of services, and coordination, collaboration and learning in the system. At the outcome level, topics include the acquisition of skills, changes in behaviours and livelihood transformations. All metrics are operationalized through a scoring mechanism. EAS-Y is digitally enabled through the Kobo toolbox and is used for participatory assessments in various contexts. Assessments can support a systematic cross country analysis, complementing findings from more specific impact evaluations of EAS interventions or in-depth process evaluations. As such, it contributes to substantially enhance EAS system performance and outcomes by guiding investment and policy decisions.