Project Management guide · Cost and resources
Project Budget: How to Create One, With an Example
A project budget is the total approved funding for a project, broken down by work and time. It is built from cost estimates, plus contingency reserves for known risks and a management reserve for unknown ones.
Key takeaways
- The budget is built from work estimates, contingency and management reserve.
- The cost baseline (BAC) is what performance is measured against.
- Time-phase the budget so cash flow and progress can be tracked.
- Change the baseline only through formal change control.
What a project budget includes
- Labour: internal staff time and contractors.
- Materials, equipment, software and licences.
- Facilities, travel and training.
- Supplier and subcontract costs; see procurement.
- Indirect costs or overheads, if the organisation allocates them.
- Contingency reserve for identified risks.
- Management reserve for unforeseen work within scope.
How the budget builds up
| Layer | What it contains | Who controls it |
|---|---|---|
| Activity estimates | Cost of each activity | Team |
| Work package estimates | Activities rolled up | Control account manager |
| Contingency reserve | Money for identified risks (known unknowns) | Project manager |
| Cost baseline | Work packages + contingency, time-phased | Project manager |
| Management reserve | Money for unknown unknowns | Sponsor |
| Project budget | Cost baseline + management reserve | Sponsor / organisation |
The cost baseline is also the budget at completion used in earned value.
How to create a project budget
- Start from a clear scope and work breakdown structure.
- Estimate the cost of each work package; see cost estimation.
- Add contingency based on risk analysis.
- Spread the costs over time using the schedule to create a time-phased baseline and S-curve.
- Add management reserve and check funding limits and cash flow.
- Get the budget approved and baselined.
- Track actuals against it and change it only through change control.
Worked example
| Item | Amount |
|---|---|
| Work packages (design, build, test, deploy) | $180,000 |
| Contingency reserve for identified risks | $20,000 |
| Cost baseline (BAC) | $200,000 |
| Management reserve | $15,000 |
| Total project budget | $215,000 |
If an identified risk occurs, the project manager draws on the $20,000 contingency. If unforeseen in-scope work appears, the sponsor may release management reserve, which then raises the cost baseline through a change request.
Tips for managing a budget
- Review actuals weekly, not only at month-end.
- Use earned value, not spend alone, to judge performance.
- Agree control thresholds, for example a CPI below 0.95 triggers a review.
- Record why reserves were used, for lessons learned.
- Check the funding schedule so money is available when it is needed.
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Frequently asked questions
What is a project budget?
The total approved funding for a project, built from cost estimates plus contingency and management reserves, and spread over time.
What is the difference between the cost baseline and the project budget?
The cost baseline includes work estimates and contingency reserve. The project budget adds the management reserve on top.
What is a contingency reserve in a project budget?
Money set aside for identified risks, held within the cost baseline and usually controlled by the project manager.
What is a management reserve in a project budget?
Money for unforeseen work within scope. It sits outside the cost baseline and is controlled by the sponsor or management.
How do you create a project budget?
Estimate each work package, add contingency, time-phase it with the schedule, add management reserve and get it approved.
How much contingency should a project budget have?
It should come from risk analysis rather than a fixed rule. Riskier, less well-defined projects need more.
What is a time-phased project budget?
A budget showing how much is planned to be spent in each period. Plotted cumulatively it forms an S-curve.
Who approves the project budget?
Usually the project sponsor or a governance board, in line with the organisation's financial authority levels.
Can a project budget change?
Yes, but only through formal change control, with the baseline updated once the change is approved.
What is budget at completion in a project budget?
The total cost baseline for the work, written BAC. It excludes management reserve.
What tools help manage a project budget?
Spreadsheets work for small projects; larger ones use project management software or finance systems with timesheets and budget tracking.