Cost Variance Calculator
Calculate Cost Variance step by step: CV = EV − AC.
In short
Formula: CV = EV − AC. CV% = CV ÷ EV.
What this calculator does
Calculate Cost Variance step by step: CV = EV − AC. Worked example, questions and limitations included.
Use it to turn Currency (symbol only, never converted), Earned value (EV), Actual cost (AC) into a checked result you can compare, copy, or rerun with different assumptions.
The page shows the formula, a numeric worked example, and the assumptions that affect this earned value calculation.
Inputs and what they mean
- Currency (symbol only, never converted)
- — choice value.
- Earned value (EV)
- — number value.
- Actual cost (AC)
- — number value.
How to use it
- Enter each value in the unit shown next to the box (use the unit converter first if your numbers are in other units).
- Check the breakdown to see every intermediate step.
- Read the limitations before relying on the result.
Formula
Definitions follow the PMI PMBOK Guide and the ANSI/EIA-748 earned value management standard.
Positive CV means the work done cost less than its budget; negative means an overrun.
CV is a cumulative figure unless you enter period values.
CV = EV − AC. CV% = CV ÷ EV.
Inputs used: Currency (symbol only, never converted), Earned value (EV), Actual cost (AC).
Worked example
EV $175,000, AC $190,000
- CV = 175,000 − 190,000 = −$15,000 (over budget).
- CV% = −15,000 ÷ 175,000 = −8.57%.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
- Cumulative values only; enter period values yourself for period variance.
- Does not identify which tasks caused the variance.
- Relies on AC and EV being measured on the same cost basis.
- Results are planning estimates built only from the figures you enter. They are not a guarantee of cost, schedule or delivery, and they do not replace your organisation's own project controls.
- The result depends on the values you enter for this cost variance calculator; it does not supply missing rates, rules, prices, dates, or assumptions for you.
Common questions
Is a positive CV always good?
Usually, but check it is real: under-reported actuals or missing accruals also produce a positive CV. Check the formula, example, and limitations on this page before using the result for a real earned value decision.
What CV% should trigger action?
There is no universal threshold. Organisations set their own variance thresholds in the project management plan.
Why divide by EV, not BAC?
CV% compares the overrun with the work actually done, which is the standard PMBOK definition. Check the formula, example, and limitations on this page before using the result for a real earned value decision.
How do I use the Cost Variance Calculator?
Enter the required values for Currency (symbol only, never converted), Earned value (EV), Actual cost (AC). The calculator applies the formula on this page and shows the main result with any supporting breakdown so you can check the arithmetic.
What formula does the Cost Variance Calculator use?
CV = EV − AC. CV% = CV ÷ EV. The visible formula section above lists the calculation path and the edge cases the page handles, so the result can be checked without relying on the form alone.
Can the Cost Variance Calculator be used for exact decisions?
Use it as a calculation aid, not as a substitute for checking the underlying rule, contract, policy, or professional advice that applies to your situation. When a result depends on local rules, personal details, prices, or dates, enter those values yourself and confirm them before acting.
Related tools
Calculate Planned Value step by step: PV = BAC × planned % complete at the status date.
Calculate Earned Value step by step: EV = BAC × actual % complete.
Calculate Actual Cost (Earned Value) step by step: AC = sum of all costs actually incurred for the work performed to the status date.
Calculate Budget At Completion step by step: BAC = sum of the budgets of all work packages in the performance measurement baseline.