Budget at Completion (BAC) & EAC Calculator
Project Budget Calculator
Enter your project’s cost and value data to estimate the final cost using Budget at Completion (BAC) and performance indices.
What is Budget at Completion (BAC)?
The Budget at Completion (BAC) is a crucial concept in project management, particularly within Earned Value Management (EVM). It represents the total budgeted cost of a project or work package *before* the project begins or at a specific baseline point. Essentially, it’s the original, planned total cost expected for all the work scheduled to be performed.
The Budget at Completion serves as the baseline against which project performance (cost and schedule) is measured. As the project progresses, the actual costs (AC) and the value of work completed (Earned Value – EV) are compared to the BAC and the Planned Value (PV) to determine if the project is on budget and on schedule.
Who Should Use Budget at Completion?
- Project Managers: To establish a cost baseline and track performance.
- Program Managers: To oversee multiple projects and their budgets.
- Cost Controllers: To monitor and control project expenditures against the Budget at Completion.
- Stakeholders: To understand the planned investment and track financial performance.
Common Misconceptions
A common misconception is that the Budget at Completion (BAC) is the same as the Estimate at Completion (EAC). While BAC is the *original* total budget, EAC is the *forecasted* total cost based on project performance and is calculated as the project progresses. The EAC may or may not be the same as the BAC.
Budget at Completion (BAC) in Formulas and Mathematical Explanation
The Budget at Completion (BAC) itself is typically a given value – the sum of all budgeted costs for the project. However, it is a key component in calculating other important Earned Value Management (EVM) metrics, particularly the Estimate at Completion (EAC).
Here’s how BAC is used:
- Cost Performance Index (CPI): CPI = EV / AC (Earned Value / Actual Cost)
- Estimate at Completion (EAC) – Assuming current CPI continues: EAC = BAC / CPI
- Estimate at Completion (EAC) – Assuming remaining work at budgeted rate: EAC = AC + (BAC – EV)
- Estimate to Complete (ETC) – Based on CPI: ETC = (BAC – EV) / CPI
- Variance at Completion (VAC): VAC = BAC – EAC
The Budget at Completion is the starting point for these calculations, providing the baseline budget.
Variables Table
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| BAC | Budget at Completion | Currency ($) | Positive value |
| AC (ACWP) | Actual Cost (of Work Performed) | Currency ($) | Positive value |
| EV (BCWP) | Earned Value (Budgeted Cost of Work Performed) | Currency ($) | Positive value, <= BAC |
| PV (BCWS) | Planned Value (Budgeted Cost of Work Scheduled) | Currency ($) | Positive value |
| CPI | Cost Performance Index | Ratio | >0, ideally >=1 |
| SPI | Schedule Performance Index | Ratio | >0, ideally >=1 |
| EAC | Estimate at Completion | Currency ($) | Positive value |
| ETC | Estimate to Complete | Currency ($) | Positive value |
| VAC | Variance at Completion | Currency ($) | Positive or negative |
Practical Examples (Real-World Use Cases)
Example 1: Software Development Project
A software project has a Budget at Completion (BAC) of $150,000. After three months, the team has incurred Actual Costs (AC) of $70,000, and the Earned Value (EV) is $60,000. The Planned Value (PV) was $65,000.
- BAC = $150,000
- AC = $70,000
- EV = $60,000
- PV = $65,000
CPI = EV / AC = $60,000 / $70,000 = 0.857
SPI = EV / PV = $60,000 / $65,000 = 0.923
EAC (using CPI) = BAC / CPI = $150,000 / 0.857 = $175,029
The project is over budget (CPI < 1) and behind schedule (SPI < 1). The forecasted cost at completion (EAC) is $175,029, significantly higher than the original Budget at Completion.
Example 2: Construction Project
A small building project has a Budget at Completion (BAC) of $500,000. Mid-way, AC = $280,000 and EV = $300,000. PV was $290,000.
- BAC = $500,000
- AC = $280,000
- EV = $300,000
- PV = $290,000
CPI = EV / AC = $300,000 / $280,000 = 1.071
SPI = EV / PV = $300,000 / $290,000 = 1.034
EAC (using CPI) = BAC / CPI = $500,000 / 1.071 = $466,853
The project is currently under budget (CPI > 1) and ahead of schedule (SPI > 1). The forecasted cost is now lower than the original Budget at Completion.
How to Use This Budget at Completion & EAC Calculator
- Enter Budget at Completion (BAC): Input the total original budget for your project.
- Enter Actual Cost (AC): Input the total costs incurred to date.
- Enter Earned Value (EV): Input the value of the work completed so far, based on the original budget.
- Enter Planned Value (PV) (Optional): If you want to see the Schedule Performance Index (SPI), enter the Planned Value.
- Enter New ETC (Optional): If you have a bottom-up re-estimate for the remaining work, enter it here.
- Click “Calculate EAC”: The calculator will display the EAC (using CPI) as the primary result, along with CPI, SPI (if PV entered), ETC, VAC, and EAC calculated using other methods.
- Review Results: Analyze the primary EAC, intermediate values, chart, and table to understand your project’s cost performance and forecast. If CPI is less than 1, your project is likely over budget, and the EAC will be higher than the Budget at Completion.
Key Factors That Affect Budget at Completion & EAC Results
- Accuracy of Initial BAC: An unrealistic initial Budget at Completion will lead to misleading performance indicators. Learn more about {related_keywords[0]} to improve accuracy.
- Scope Changes: Uncontrolled scope creep significantly impacts costs and can make the original BAC irrelevant without formal re-baselining.
- Resource Costs: Fluctuations in labor, material, or equipment costs directly affect AC and thus influence EAC.
- Project Risks: Realized risks (unforeseen problems) often increase costs beyond the planned Budget at Completion. Understanding {related_keywords[1]} is crucial.
- Team Productivity & Efficiency: Higher or lower than expected productivity impacts how much work is done (EV) for the cost incurred (AC), affecting CPI and EAC.
- Accuracy of EV Measurement: How Earned Value is measured needs to be consistent and accurate for CPI and EAC to be reliable. Explore {related_keywords[2]} techniques.
- Inflation and Economic Factors: For long projects, inflation can increase costs beyond original estimates in the Budget at Completion.
Frequently Asked Questions (FAQ)
Q1: What is the difference between Budget at Completion (BAC) and Estimate at Completion (EAC)?
A1: BAC is the original total budget planned for the project. EAC is the forecasted total cost of the project based on performance to date and expectations for the future.
Q2: When is the Budget at Completion (BAC) determined?
A2: The BAC is determined during the project planning phase, before significant work begins. It’s part of the project baseline.
Q3: Can the Budget at Completion (BAC) change during a project?
A3: Yes, the BAC can change, but only through a formal change control process, typically when there are approved changes to the project scope. This results in a re-baselined BAC.
Q4: What does a CPI of less than 1 mean in relation to BAC?
A4: A CPI less than 1 means the project is over budget relative to the work completed. If this trend continues, the EAC will likely exceed the Budget at Completion (BAC).
Q5: Which EAC formula is the best to use?
A5: The best EAC formula depends on the project context. EAC = BAC / CPI is common if past performance is expected to continue. EAC = AC + (BAC – EV) assumes remaining work is at the budgeted rate. EAC = AC + New ETC is used when a new estimate is more reliable. Consider {related_keywords[3]} for complex scenarios.
Q6: What is Variance at Completion (VAC)?
A6: VAC = BAC – EAC. It shows the expected variance (overrun or underrun) from the original Budget at Completion at the end of the project based on current forecasts.
Q7: How is Earned Value (EV) calculated?
A7: EV is calculated based on the percentage of work completed for each task multiplied by its budgeted cost. Different methods exist, like 0/100, 50/50, or percentage complete.
Q8: Does this calculator account for schedule variance affecting costs?
A8: Indirectly. If schedule delays (SPI < 1) lead to increased costs (e.g., extended resource usage), this will reflect in a higher AC and lower CPI, impacting the EAC relative to the Budget at Completion.
Related Tools and Internal Resources
- {related_keywords[0]}: Learn how to create accurate initial project budgets.
- {related_keywords[1]}: Understand how to manage risks that can impact your project’s final cost compared to the Budget at Completion.
- {related_keywords[2]}: Explore different methods for measuring Earned Value accurately.
- {related_keywords[3]}: Delve deeper into advanced forecasting techniques beyond the basic EAC formulas.
- {related_keywords[4]}: Understand how scope changes impact the Budget at Completion and how to manage them.
- {related_keywords[5]}: Get a comprehensive overview of Earned Value Management principles.