While trust is increasingly used to discuss the responsibility of platforms in the online ecosystem, measuring it has been significantly challenging. In our research, we have learned that users employ complex mental heuristics when making trust choices, mediated by their lived experiences, their situation in entangled systems, and sociocultural context. Additionally, within the idea of trust itself, there may be subcategories of trust in an outcome, trust in the process regardless of outcome, or trust in particular contexts. In this talk, we'll outline the challenges of measuring trust quantitatively and qualitatively, and considerations in metric design. You'll learn possible methods of measuring trust, analogous constructs for trust, and how much trust is “just the right amount”.