Cost Performance Index (CPI) Calculator
Earned Value Breakdown
| Planned Value (PV) | $250,000 |
| Earned Value (EV) | $220,000 |
| Actual Cost (AC) | $240,000 |
| Budget at Completion (BAC) | $600,000 |
| Cost Performance Index (CPI) | 0.92 |
| Schedule Performance Index (SPI) | 0.88 |
| Cost Variance (CV) | $-20,000 |
| Schedule Variance (SV) | $-30,000 |
| Variance at Completion (VAC) | $-54,545 |
| To-Complete Performance Index (TCPI) | 1.06 |
| Estimate at Completion (EAC) | $654,545 |
Summary Statistics
What Is the Cost Performance Index?
The Cost Performance Index (CPI) is the core earned value metric that tells you how efficiently your project is converting every dollar of actual spend into earned value. It is calculated by dividing Earned Value by Actual Cost: a CPI of 1.0 means you are getting exactly one dollar of completed work for every dollar spent, above 1.0 means you are ahead of the cost curve, and below 1.0 means you are over budget. Because it is a ratio rather than a dollar figure, CPI lets you compare cost health across projects of any size, and it is the single best leading indicator of whether a project will finish within its budget. The metric comes from earned value management, the discipline of measuring project performance in money rather than in task completion alone — a task that is half done is worth half its budgeted value, whether the team spent the full amount or not, which is what makes the comparison honest.
How the Earned Value Metrics Work Together
The calculator uses the three classic earned value inputs. Planned Value (PV) is the budgeted cost of work scheduled to be done by now, Earned Value (EV) is the budgeted cost of work actually performed, and Actual Cost (AC) is what that work really cost. CPI divides EV by AC, while the Schedule Performance Index (SPI) divides EV by PV to measure time efficiency. Cost Variance (CV) and Schedule Variance (SV) express the same health in dollars: EV minus AC and EV minus PV. The forward-looking numbers use the current CPI to extrapolate: Estimate at Completion (EAC) divides the Budget at Completion (BAC) by CPI, producing the most probable final cost if today's efficiency holds for the rest of the project. Variance at Completion (VAC) subtracts EAC from BAC to show the expected overrun or underrun in dollars, and the To-Complete Performance Index (TCPI) divides the remaining work by the remaining funds — the efficiency the team must achieve from here to finish on budget. A TCPI above 1.0 means the remaining work must be done more efficiently than the project has managed so far, which is the earliest warning that a budget change request is coming.
Understanding Your Results
A CPI below 1.0 should trigger a root-cause review of the largest cost drivers — labor rates, material overruns, or scope growth — because the EAC line shows the trajectory if current efficiency holds. A common trap is reading a healthy SPI as permission to ignore cost: a project can be ahead of schedule while burning cash, so always read CPI and SPI together. If the TCPI is meaningfully above your current CPI, plan for a budget change request or a scope reduction, since finishing on budget would require better efficiency than the project has demonstrated. Recompute these figures at every reporting period; the trends matter more than any single snapshot. A CPI that drifts from 1.05 to 1.01 across three reports is a warning sign even while the number stays green, and a project that recovers from 0.92 to 0.97 is usually correcting faster than one that holds steady at 0.85. Track the direction as much as the level.
Related Calculators
Home Loan Calculator
Calculate home loan EMI, total interest, and amortization schedule.
Auto Loan Calculator
Detailed auto loan with trade-in, taxes, fees, and amortization.
Bike Loan Calculator
Calculate bike loan EMI, total cost, and repayment breakdown.
Boat Loan Calculator
Estimate boat financing payments, interest, and amortization.
Student Loan Calculator
Calculate student loan payments with income-driven repayment plans.
Gold Loan Calculator
Calculate gold loan amount based on gold weight, purity, and LTV ratio.
USDA Loan Calculator
Calculate USDA loan payments with guarantee fee and income eligibility.
Loan Against Property Calculator
Calculate LAP EMI based on property value and loan-to-value ratio.