Estimate at Completion (EAC) Calculator
Enter your Budget at Completion, Earned Value, Actual Cost and Planned Value to forecast the final cost of your project. This tool computes all four standard PMBOK EAC methods at once, so you can see the optimistic and pessimistic forecasts side by side.
How do you calculate Estimate at Completion?
The most common Estimate at Completion formula is EAC = BAC / CPI, where CPI (Cost Performance Index) = EV / AC. It projects the final cost by assuming the cost efficiency seen so far continues to the end. Three other PMBOK methods handle different situations: EAC = AC + (BAC - EV) when the overrun was a one-off, EAC = AC + (BAC - EV) / (CPI x SPI) when the project is both over budget and behind schedule, and EAC = AC + ETC when you have re-estimated the remaining work by hand.
Quick-fill presets
Required Inputs
Optional
Leave ETC blank to compute the three formula-based EAC methods. Add it to also get the bottom-up forecast (EAC = AC + ETC). PV is only needed for the cost-plus-schedule method.
Nothing is stored. All calculation runs in your browser.
The four EAC formulas, and when each applies
| Method | Formula | Assumption |
|---|---|---|
| Typical variance | EAC = BAC / CPI | Current cost efficiency continues to the end. The default forecast. |
| Atypical variance | EAC = AC + (BAC - EV) | The overrun to date was a one-off; remaining work runs at the budgeted rate. |
| Cost + schedule | EAC = AC + (BAC - EV) / (CPI x SPI) | Both cost and schedule performance drag on the remaining work. Usually the most pessimistic. |
| Bottom-up | EAC = AC + ETC | You re-estimate the remaining work (ETC) directly and trust it over any formula. |
All four are standard in the PMI PMBOK Guide. They disagree because they make different assumptions about how the past predicts the future, not because any is arithmetically wrong. Reporting the typical and cost-plus-schedule methods together gives sponsors a realistic range.
Worked example
A 12-month project. BAC = $2,000,000. At month 6: PV = $1,100,000, EV = $900,000, AC = $1,050,000.
| CPI | EV / AC = 900,000 / 1,050,000 | 0.857 |
| SPI | EV / PV = 900,000 / 1,100,000 | 0.818 |
| EAC (typical) | BAC / CPI = 2,000,000 / 0.857 | $2,333,333 |
| EAC (atypical) | AC + (BAC - EV) = 1,050,000 + 1,100,000 | $2,150,000 |
| EAC (cost + schedule) | AC + (BAC - EV) / (CPI x SPI) | $2,618,519 |
The three formula methods forecast a final cost between $2.15M and $2.62M, an overrun of roughly 8% to 31% on the $2M budget. The cost-plus-schedule figure ($2,618,519) is the pessimistic case because the project is behind on both cost and schedule; the typical figure ($2,333,333) is the one most teams report.
Frequently asked questions
What is Estimate at Completion (EAC)?
EAC is the forecast total cost of a project once finished, based on performance to date. Unlike the Budget at Completion (BAC), which is fixed at approval, EAC is re-forecast during delivery from the cost efficiency the project is actually running at. A negative Variance at Completion (VAC = BAC - EAC) is a forecast overrun.
What are the four EAC formulas?
(1) EAC = BAC / CPI assumes current cost efficiency continues. (2) EAC = AC + (BAC - EV) assumes remaining work runs at the budgeted rate. (3) EAC = AC + (BAC - EV) / (CPI x SPI) assumes both cost and schedule performance affect remaining work. (4) EAC = AC + ETC uses a fresh bottom-up Estimate to Complete.
Which EAC formula should I use?
Use BAC / CPI as the default when the cost variance is typical and likely to continue. Use AC + (BAC - EV) when the overrun was a one-off. Use the CPI x SPI method when the project is both over budget and behind schedule. Use AC + ETC when you have re-estimated the remaining work bottom-up and trust that over any formula.
What is the difference between EAC and ETC?
ETC (Estimate to Complete) is the forecast cost of the remaining work only. EAC (Estimate at Completion) is the forecast cost of the whole project: the money already spent plus the ETC. So EAC = AC + ETC.