PMP Formulas: The Complete List with Definitions and Examples (2026)
The core PMP formulas are earned value and forecasting:
Cost Variance CV = EV − AC
Schedule Variance SV = EV − PV
Cost Performance Index CPI = EV / AC
Schedule Performance Index SPI = EV / PV
Estimate at Completion EAC = BAC / CPI
PERT expected duration (O + 4M + P) / 6
Number of communication channels n(n − 1) / 2
Last updated 14 September 2026 · Reflects the PMP Examination Content Outline effective 9 July 2026.
Are formulas still on the PMP exam in 2026?
A revised PMP Examination Content Outline took effect on 9 July 2026, replacing the January 2021 version and rebalancing the exam toward People (33%), Process (41%) and Business Environment (26%). The exam now leans firmly toward scenario judgement rather than memorised calculation. In practice a small share of questions still involve formulas — most often asking you to interpret a value ("CPI is 0.84 — what does that mean?") rather than perform arithmetic. Earned value management is the most likely area to appear. The formulas below are grouped so you can see which are worth knowing for the current exam and which are general project-management knowledge.
Flag key: Core exam expect it · Lighter may appear, interpretation-focused · Reference general PM knowledge or de-emphasized by PMI.
Earned value inputs
Every earned value formula is built from four values. Planned Value (PV) is the budgeted cost of the work scheduled by now. Earned Value (EV) is the budgeted value of the work actually completed. Actual Cost (AC) is what has actually been spent. Budget at Completion (BAC) is the total approved budget. A single scenario runs through the examples below: BAC $500,000, PV $300,000, EV $270,000, AC $320,000.
Variances and performance indices Core exam
| Metric | Formula | How to read it |
|---|---|---|
| Cost Variance (CV) | CV = EV − AC | Positive is under budget; negative is over |
| Schedule Variance (SV) | SV = EV − PV | Positive is ahead; negative is behind |
| Cost Performance Index (CPI) | CPI = EV / AC | Above 1.0 under budget; below 1.0 over |
| Schedule Performance Index (SPI) | SPI = EV / PV | Above 1.0 ahead; below 1.0 behind |
Cost Variance (CV)
Cost Variance is defined as earned value minus actual cost. It shows, in money, whether completed work cost more or less than budgeted. Negative is over budget.
Example: 270,000 − 320,000 = −$50,000 — the project is $50,000 over budget.
Schedule Variance (SV)
Schedule Variance is defined as earned value minus planned value. It expresses schedule progress in cost terms: how much more or less work is done than planned. Negative is behind schedule.
Example: 270,000 − 300,000 = −$30,000 — behind schedule.
Cost Performance Index (CPI)
CPI is defined as earned value divided by actual cost. It measures cost efficiency: 0.84 means the project earns 84 cents of value per dollar spent. Below 1.0 is over budget.
Example: 270,000 / 320,000 = 0.84 — over budget.
Schedule Performance Index (SPI)
SPI is defined as earned value divided by planned value. It measures progress efficiency against the plan: 0.90 means work is proceeding at 90% of the planned rate. Below 1.0 is behind.
Example: 270,000 / 300,000 = 0.90 — behind schedule.
Forecasting formulas Lighter
| Metric | Formula | When to use |
|---|---|---|
| EAC (typical) | EAC = BAC / CPI | Current cost efficiency continues (exam default) |
| EAC (atypical) | EAC = AC + (BAC − EV) | Overrun was a one-off; rest runs to plan |
| EAC (cost + schedule) | EAC = AC + [(BAC − EV) / (CPI × SPI)] | Both cost and schedule performance persist |
| ETC | ETC = EAC − AC | Cost of the remaining work |
| VAC | VAC = BAC − EAC | Projected over/under budget at finish |
| TCPI (to budget) | TCPI = (BAC − EV) / (BAC − AC) | Efficiency needed to still hit the budget |
Estimate at Completion (EAC)
EAC is defined as the forecast total cost of the project given performance so far. The exam-default version, budget at completion divided by CPI, assumes current cost efficiency continues to the end. Use the atypical version when the overrun was a one-time event, and the combined version when both cost and schedule performance are expected to persist.
Example (typical): 500,000 / 0.84 ≈ $592,600.
To-Complete Performance Index (TCPI)
TCPI is defined as the cost efficiency the remaining work must reach to hit a chosen target. Against the original budget it is (BAC − EV) / (BAC − AC). A result above 1.0 means the rest of the work must run more efficiently than the budget allowed.
Example: (500,000 − 270,000) / (500,000 − 320,000) = 1.28 — the remaining work would need 128% efficiency, unlikely when current CPI is 0.84.
Estimation: PERT and three-point Lighter
The PERT (beta) estimate is defined as a weighted average that gives the most-likely case four times the weight of the optimistic and pessimistic extremes, producing a more realistic figure than a plain average. The triangular estimate is a simple unweighted average, used only when a question asks for it.
| Estimate | Formula |
|---|---|
| PERT / beta | E = (O + 4M + P) / 6 |
| Triangular | E = (O + M + P) / 3 |
| Standard deviation | SD = (P − O) / 6 |
Example: O = 8, M = 10, P = 18 → beta = (8 + 40 + 18) / 6 = 11 days; triangular = 36 / 3 = 12 days.
Communication channels Core exam
The number of communication channels is defined as the count of unique two-way paths among a group of people. It grows non-linearly as people are added, which is why it is used to illustrate stakeholder complexity. Remember to include yourself, the project manager, in the count.
Channels = n(n − 1) / 2
Example: 7 stakeholders plus the PM gives n = 8 → 8 × 7 / 2 = 28 channels.
Point of Total Assumption Reference
The Point of Total Assumption is defined, for a fixed-price-incentive-fee contract, as the cost level above which the seller absorbs all further overrun. PMI has de-emphasized this concept and it is unlikely on the current exam; it is included here because it is still searched.
PTA = [(Ceiling Price − Target Price) / Buyer's Share Ratio] + Target Cost
Frequently asked questions
What is CPI and how do you calculate it?
CPI, the Cost Performance Index, is earned value divided by actual cost (CPI = EV / AC). It measures how much value the project earns per unit of cost. A CPI above 1.0 means the project is under budget; below 1.0 means over budget.
How do you calculate EAC?
The most common Estimate at Completion formula is EAC = BAC / CPI, which assumes current cost efficiency continues. Other versions apply when the overrun was a one-off (EAC = AC + BAC − EV) or when both cost and schedule performance are expected to continue (EAC = AC + [(BAC − EV) / (CPI × SPI)]).
What is the earned value formula?
Earned Value (EV) is the budgeted value of the work actually completed: EV = actual percent complete × BAC. It is the anchor for the variance, index and forecasting formulas.
What is the difference between CV and SV?
Cost Variance (CV = EV − AC) compares earned value against money spent, showing budget status. Schedule Variance (SV = EV − PV) compares earned value against planned value, showing schedule status. Both are positive when the project is healthy.
What is the communication channels formula?
The number of communication channels is n(n − 1) / 2, where n is the total number of people involved, including the project manager. For 8 people that is 28 channels.
Are PMP formulas still tested in 2026?
Yes, but lightly. Under the Exam Content Outline effective 9 July 2026 the exam emphasizes scenario judgement over calculation. A small number of questions involve formulas, usually asking you to interpret a value rather than compute one, with earned value management the most likely area.
