What is CPI and what does it mean?

Cost Performance Index (CPI) = Earned Value (EV) / Actual Cost (AC). A CPI of 1.0 means you are spending exactly as planned. Above 1.0 means you are getting more value per dollar spent (under budget). Below 1.0 means you are overspending for the work delivered (over budget). A CPI of 0.85 means every dollar spent returns only 85 cents of planned value.

What is SPI and what does it mean?

Schedule Performance Index (SPI) = Earned Value (EV) / Planned Value (PV). An SPI of 1.0 means work is progressing exactly on schedule. Above 1.0 means you are ahead of schedule. Below 1.0 means you are behind schedule. An SPI of 0.90 means only 90% of the planned work has been completed.

What is the difference between EV, PV, and AC?

Earned Value (EV) is the budgeted amount for work you have actually completed. Planned Value (PV) is the budgeted amount for work you were supposed to complete by now according to the schedule. Actual Cost (AC) is the real money you have spent. EV is the link between schedule and cost — it turns physical progress into a dollar figure.

Can CPI and SPI be above 1 indefinitely?

In practice, CPI above 1 early in a project often normalizes as the project progresses and scope complexity increases. SPI naturally converges to 1.0 at project completion regardless of efficiency, because all planned work gets completed. CPI at completion is a more reliable long-term forecast than SPI.

What CPI or SPI value signals a serious problem?

Most PMOs treat CPI or SPI below 0.8 as a red flag requiring corrective action. A value between 0.8 and 0.95 is a warning zone. Values above 0.95 are generally acceptable with monitoring. PMBOK guidance notes that the final CPI of a project is typically within 10% of the value established by the 20% completion point.

CPI & SPI Calculator

Enter Earned Value, Planned Value, and Actual Cost to instantly compute your project's Cost Performance Index (CPI) and Schedule Performance Index (SPI) with status interpretation.

Project Values

Enter dollar amounts (or any consistent unit). Decimals OK.

Earned Value (EV) Budgeted cost of completed work

Planned Value (PV) Budgeted cost of scheduled work

Actual Cost (AC) Real money spent on completed work

Formulas

CPI= EV / AC

SPI= EV / PV

CV= EV − AC

SV= EV − PV

Enter EV, PV, and AC then click Calculate

CPI, SPI, and variance values will appear here

Summary

Compute the Cost Performance Index (CPI = EV / AC) and Schedule Performance Index (SPI = EV / PV) from your project's Earned Value, Planned Value, and Actual Cost. Results include color-coded status badges, gauge bars, and plain-English interpretation so you can spot budget or schedule problems at a glance.

How it works

Enter the Earned Value (EV) — the budgeted cost of work actually completed to date.
Enter the Planned Value (PV) — the budgeted cost of work that was scheduled to be done by now.
Enter the Actual Cost (AC) — the real money spent on the work completed to date.
Click Calculate to see CPI, SPI, Cost Variance, and Schedule Variance.
Read the status badges and interpretation text to understand project health.

Use cases

Quickly check whether a project is over budget (CPI < 1) or under budget (CPI > 1).
Determine if work is behind schedule (SPI < 1) or ahead of schedule (SPI > 1).
Prepare a concise status report for a PMO or stakeholder meeting.
Study for the PMP exam by verifying EVM index calculations.
Compare CPI and SPI side by side to diagnose whether a project has a cost problem, a schedule problem, or both.
Track project performance trends across sprint or phase boundaries.

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu