Cost Variance (CV)
CV = EV − AC- Purpose:
- Measures whether the project is over or under budget at a point in time.
- When to use:
- Positive = under budget. Negative = over budget. Always pair with SV for full picture.
Free PMP® Reference
The 12 PMP® formulas you must know for the exam
Earned Value, forecasting, PERT, communication channels, and EMV — every formula on the PMP® exam, with purpose and when-to-use notes. Bookmark this page or print it.
Most of the calculation questions on the PMP® exam fall into one of three buckets: Earned Value Management (EVM), forecasting, and a handful of one-off formulas like PERT and communication channels. The exam tests three things for each formula: what it’s for, how to calculate it, and when to apply it. Skim this reference, then drill the formulas you’re weakest on.
Earned Value
Schedule Variance (SV)
SV = EV − PV- Purpose:
- Measures whether the project is ahead of or behind schedule.
- When to use:
- Positive = ahead of schedule. Negative = behind schedule.
Cost Performance Index (CPI)
CPI = EV ÷ AC- Purpose:
- Efficiency of cost utilization — how much value you got per dollar spent.
- When to use:
- > 1.0 = under budget. < 1.0 = over budget. Most-tested EVM formula on the exam.
Schedule Performance Index (SPI)
SPI = EV ÷ PV- Purpose:
- Efficiency of time utilization.
- When to use:
- > 1.0 = ahead of schedule. < 1.0 = behind schedule.
Forecasting
Estimate at Completion (EAC) — typical
EAC = BAC ÷ CPI- Purpose:
- Forecasts total cost assuming current cost performance continues.
- When to use:
- Use when current variances are typical of future work.
Estimate at Completion (EAC) — atypical
EAC = AC + (BAC − EV)- Purpose:
- Forecasts total cost assuming remaining work is on plan.
- When to use:
- Use when the variance was a one-time event and won’t repeat.
Estimate to Complete (ETC)
ETC = EAC − AC- Purpose:
- Money still needed to finish the project from this point forward.
- When to use:
- Always derive from your chosen EAC method.
Variance at Completion (VAC)
VAC = BAC − EAC- Purpose:
- Projected total budget surplus or shortfall at project end.
- When to use:
- Positive = under budget at completion. Negative = over budget.
To-Complete Performance Index (TCPI)
TCPI = (BAC − EV) ÷ (BAC − AC)- Purpose:
- Cost performance required on remaining work to hit the original budget.
- When to use:
- If TCPI > 1.0, the team must work more efficiently than planned to recover.
Estimating
PERT (Three-Point) Estimate
PERT = (O + 4M + P) ÷ 6- Purpose:
- Weighted-average estimate using optimistic, most-likely, and pessimistic values.
- When to use:
- Use for activities with high uncertainty. Standard deviation = (P − O) ÷ 6.
Communications
Communication Channels
n × (n − 1) ÷ 2- Purpose:
- Counts the number of two-way communication channels in a project team.
- When to use:
- Almost guaranteed to appear on the exam. n = number of stakeholders.
Risk
Expected Monetary Value (EMV)
EMV = Probability × Impact- Purpose:
- Quantifies the expected financial outcome of a risk.
- When to use:
- Sum EMVs across a decision branch to compare alternatives in decision trees.
How to memorize these for exam day
- Learn EVM first. CV, SV, CPI, SPI, and EAC together account for the majority of calculation questions. Master these and you’ve covered the bulk of exam math.
- Drill communication channels until it’s automatic. The n × (n−1) ÷ 2 question shows up on nearly every PMP® exam.
- Practice spotting which EAC variant to use. Wording like “assuming current performance continues” signals BAC ÷ CPI, while “one-time event” signals AC + (BAC − EV).
- Build a one-page brain dump. On exam day, immediately write all 12 formulas on your scratch paper before answering any questions. This frees your working memory.