To illustrate the concept of EVM and all the formulas, assume a project that has exactly one task. The task was baselined at 8 hours, but 11 hours have been spent and the estimate to complete is 1 additional hour. The task would have been completed already. Assume an Hourly Rate of $100 per hour. Using this information:

Hourly Rate = $100
PV or BCWS = Hourly Rate * Total Hours Planned or Scheduled
PV = $800 ($100 * 8 hours)
AC or ACWP = Hourly Rate * Total Hours Spent
AC = $1100 ($100 * 11 hours)
EV or BCWP = Baselined Cost * % Complete Actual
EV = $734 (baseline of $800 * 91.7% complete)
(NOTE % Complete Actual (below) to get the 91.7% )
BAC = Baselined Effort-hours * Hourly Rate
BAC = $800 (8 hours * $100)
EAC = AC + ETC
EAC = $1200 (1100 + 100)
VAC = BAC - EAC
VAC = -$400 ($800 - $1200 )
% Completed Planned = PV / BAC
% Complete Planned = 100% ($800 PV / $800 BAC)
% Completed Actual = AC / EAC
% Complete Actual = 91.7% ($1100 AC / $1200 EAC)
SV = Earned Value (EV) - Planned Value (PV)
SV = -$66 ($734 EV - $800 PV)
SPI = Earned Value (EV) /Planned Value (PV)
SPI = 0.91 ($734 EV / $800 PV)
CV = Earned Value (EV) - Actual Cost (AC)
CV = -$366 ($734 EV - $1100 AC) indicating a cost overrun
CPI = Earned Value (EV) /Actual Cost (AC)
CPI = 0.66 ($734 EV / $1100 AC) indicating over budget