Cost Performance Index (CPI)

An indicator of how efficiently the project is using its budgeted resources, calculated as earned value divided by actual cost (EV/AC).

Key Points

  • Formula: CPI = EV / AC.
  • Interpretation: CPI > 1 means under budget; CPI < 1 means over budget; CPI = 1 means on budget.
  • Forecasting: A common estimate at completion is EAC = BAC / CPI when future performance is expected to mirror current trends.
  • Relationship to cost variance: CV = EV - AC; CV > 0 aligns with CPI > 1, and CV < 0 aligns with CPI < 1.

Example

Midway through a project, EV is 400,000 and AC is 500,000. CPI = 400,000 / 500,000 = 0.80, meaning the team delivers 0.80 units of value for each 1.00 unit of cost, indicating a cost overrun. If BAC is 1,200,000 and performance continues, EAC is approximately 1,200,000 / 0.80 = 1,500,000.

PMP Example Question

During a status review, a project reports EV = 250,000 and AC = 200,000. What is the CPI and what does it indicate?

  1. 0.80 - The project is over budget.
  2. 1.25 - The project is under budget.
  3. 1.25 - The project is over budget.
  4. 0.80 - The project is under budget.

Correct Answer: B - CPI of 1.25 indicates the project is under budget

Explanation: CPI = EV / AC = 250,000 / 200,000 = 1.25; a value greater than 1 means the project is achieving more value per unit of cost than planned.

Leadership for Project Managers Course

Lead with clarity, confidence, and real impact. This Leadership for Project Managers course turns day-to-day challenges—unclear priorities, tough stakeholders, and cross-functional friction—into opportunities to guide teams and deliver outcomes that matter.

You’ll learn practical leadership skills tailored to project realities: setting direction without overcontrol, creating alignment across functions, and building commitment even when authority is limited. We go beyond theory with tools you can use immediately—one-sentence visioning, stakeholder influence maps, decision framing, and feedback scripts that actually land.

Expect hands-on frameworks, real-world examples, and guided practice to prepare for tough moments—executive readouts, resistance from stakeholders, and high-stakes negotiations. Downloadable templates and checklists keep everything actionable when the pace gets intense.

Ready to influence without waiting for a bigger title? Join a community of ambitious PMs, sharpen your edge, and deliver with purpose—project after project.



Launch your career!

HK School of Management provides world-class training in Project Management, Lean Six Sigma, and Agile Methodologies. Just for the price of a lunch you can transform your career, and reach new heights. With 30 days money-back guarantee, there is no risk.

Learn More