Which of the following metrics demonstrates to a project manager if a project is overspending or under spending ?

EAC (Estimate at Completion) forecasts the total expected cost of the project at completion and does not directly indicate whether current spending is efficient or inefficient relative to work accomplished.

BAC (Budget at Completion) represents the total approved budget for the entire project and provides no information about current spending performance relative to the work that has been completed.

CPI is calculated as Earned Value (EV) divided by Actual Cost (AC), producing a ratio that measures cost efficiency at any point in the project. A CPI below 1.0 indicates the project is over budget for the work completed (overspending), while a CPI above 1.0 indicates the project is delivering more value than the cost incurred (underspending), making it the definitive metric for evaluating spending performance.

ETC (Estimate to Complete) represents the expected cost needed to finish the remaining project work and does not measure whether the project is currently over or under its planned spending rate.