The UC2 Risk Ruler is designed to simplify and enhance risk estimation by integrating both quantitative and qualitative assessments from subject matter experts. Building on the Uniform Confidence/Certainty Estimation (UC2) framework, the Risk Ruler offers a scale that adjusts and captures confidence levels in risk predictions, helping subject matter experts express estimates that vary in certainty. By aligning data-driven and expert-derived risk estimates in a unified manner, the tool addresses challenges such as false accuracy, overconfidence, and the difficulty of aggregating disparate data types. Adaptable to a variety of real-world scenarios, such as cybersecurity, national infrastructure, and beyond, it offers decision-makers both insight and transparency in risk management. The UC2 Risk Ruler also seamlessly integrates with existing risk models and workflows, providing a practical and intuitive solution for improved risk management.