Project Management Calculators

How to use each calculator

• Earned value (EVM): enter BAC, PV, EV and AC. CPI or SPI below 1.0 means over budget or behind schedule. Pick the EAC that matches the situation: BAC ÷ CPI when current cost performance will continue, AC + (BAC − EV) when the variance was a one-off, and AC + (BAC − EV) ÷ (CPI × SPI) when both cost and schedule drive the forecast.
• PERT estimate: enter optimistic, most likely and pessimistic values. The beta (PERT) mean weights the most likely value four times; the triangular mean weights all three equally. Standard deviation is (P − O) ÷ 6.
• Critical path and float: list activities with durations and finish-to-start predecessors. The calculator runs the forward and backward pass and shows ES, EF, LS, LF, total float and free float. Activities with zero total float are on the critical path.
• ROI and payback: enter the initial investment and the net cash inflow for each period. ROI = (gain − cost) ÷ cost. Payback is the point where cumulative cash flow turns positive. Neither accounts for the time value of money.
• Budget and reserves: add work package estimates, then contingency reserve for identified risks to get the cost baseline. Add management reserve for unidentified risks to get the total project budget. The cost baseline is what earned value is measured against.

Exam tips

• On the PMP exam, questions usually give you the inputs and ask you to interpret the result, for example what a CPI of 0.9 says about the project, rather than only to calculate it.
• Variances: negative is bad, positive is good. Indexes: below 1.0 is bad, above 1.0 is good. TCPI is the exception: above 1.0 means the remaining work must be done more efficiently.
• Management reserve is not part of the cost baseline, so it is not included in BAC.

Keep learning

• PMP formula cheat sheet: every formula on one page, with when to use each.
• Decision Lab: practice the judgment behind situational questions.
• Free mock exam: 50 timed questions to see where you stand.
• Certification guides: eligibility, exam format and renewal, from official sources.

Last reviewed: October 8, 2026. Formulas follow standard PMI earned value and scheduling conventions as taught for the PMP exam. PM Exam Lab is independent and not affiliated with or endorsed by PMI.