How do you calculate the Estimate at Completion using CPI?

The Estimate at Completion, or EAC, forecasts the total project cost based on current performance. The most common formula is Budget at Completion divided by CPI, written as EAC equals BAC divided by CPI. This assumes current cost performance will continue for the remaining work. For example, if the total budget is 100,000 dollars and the CPI is 0.8, the EAC is 125,000 dollars, meaning the project will cost 25,000 dollars more than planned.