This guide serves as a comprehensive handbook for calculating event return on investment (ROI). It details the challenges faced in measuring ROI for events, particularly due to the difficulty in quantifying certain benefits like brand awareness and customer loyalty. The handbook outlines a seven-step process to effectively forecast and measure event ROI. Steps include choosing an appropriate calculation metric, identifying primary goals, setting measurable objectives, and gathering relevant data throughout the event lifecycle. Additionally, it emphasizes the importance of aligning the event strategy with clear goals to effectively pitch to executives. After the event, the guide recommends analyzing results against forecasts and identifying areas for improvement. Tools and techniques for data collection, such as feedback forms and social media analysis, are also discussed to enhance the accuracy of ROI measurements. The handbook aims to equip marketers with the necessary skills and knowledge to present a compelling case for events despite economic constraints.