Project Budget Burn Calculator
Estimate project budget burn from spend, commitments, dates, and progress, then compare forecast methods, runway, EVM signals, and review exports.{{ summaryHeading }}
Current result
| Metric | Value | Review note | Copy |
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| Method | Formula basis | Forecast final spend | Variance | Signal | Copy |
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| {{ row.method }} Selected | {{ row.formula }} | {{ row.forecast }} | {{ row.variance }} | {{ row.signal }} |
| Schedule item | Value | Detail | Copy |
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| Checkpoint | Signal | Review note | Copy |
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| {{ row.checkpoint }} | {{ row.signal }} | {{ row.note }} |
Introduction:
A project can look affordable in the ledger and still be heading toward an overrun. Posted spend shows what has already hit the accounts, but commitments, unfinished work, schedule pace, and reserve policy decide how much room is really left.
Project budget burn reviews cost at a status date, which is the cut-off date for the latest snapshot. The review becomes more useful when money is read with progress and time instead of as a simple "spent so far" number. Spending half the budget halfway through the schedule may be healthy for an even-spend project, but risky when only a third of the work is complete.
Several terms matter because they answer different questions:
- Approved budget
- The baseline amount used to judge the final cost, often called budget at completion in earned value work.
- Actual spend
- Cost already posted or invoiced by the status date.
- Committed cost
- Approved obligations such as purchase orders, contractor bookings, or vendor commitments that may not have become actual spend yet.
- Percent complete
- The portion of planned work accepted or judged complete, preferably tied to milestones or earned value rather than optimism.
A useful burn review separates cost that has already happened from cost that is likely to happen. Committed cost is easy to forget because it may not appear in accounting actuals yet, but it reduces the budget available for new decisions. A project with low actual spend and large commitments can be closer to the budget line than the ledger alone suggests.
Forecasting method matters. A time-based view assumes cost should move with the calendar. A percent-complete view assumes progress reporting is trustworthy. A planned-spend ratio compares actual cost with what the budget expected by the same status date. A bottom-up remaining estimate can be better than pace-based math when the team has a current view of unfinished work.
Budget burn is a control signal, not a verdict. It can show that a project deserves attention, a reserve check, or a reforecast conversation. It cannot prove that the final cost is fixed, because scope changes, late invoices, procurement timing, and progress measurement quality can all move the answer.
How to Use This Tool:
Enter a status-date snapshot first, then choose the forecast method that matches how the project is being managed.
- Fill in Total budget, Actual spend to date, and Committed cost. Use the approved baseline for the budget, posted cost for actual spend, and approved but unposted obligations for commitments.
- Set Project start date, Project end date, and Status date. The status date should be the same cut-off date used for the actual and committed cost snapshot.
- Enter Percent complete from the project status report, earned value record, or accepted milestone progress. The number field and slider both update the same progress value.
- Choose Primary forecast method. Use Time-based burn rate for schedule-paced spend, Percent-complete estimate when progress is stronger than elapsed time, Planned-spend burn ratio when planned spend is available, or Manual remaining estimate when a current bottom-up estimate should drive the forecast.
A method can show Unavailable when its denominator is missing, such as zero elapsed time, zero percent complete, or no planned spend at the status date.
- Open Advanced when you need to change the display currency, enter Planned spend at status date, set a Reserve cushion, adjust the Overrun alert threshold, or change rounding. The currency field changes labels only and does not convert exchange rates.
- If validation errors appear, fix the named field before reading results. Common recoveries are entering a budget greater than zero, keeping percent complete between 0 and 100, using valid dates, and setting the project end date on or after the start date.
- Start with the summary badges and Burn Snapshot, then compare Forecast Methods, Schedule Check, Budget Review Brief, and the two chart tabs before copying or downloading a review artifact.
Interpreting Results:
Selected forecast final spend is the completion estimate from the chosen forecast method after applying the committed-cost floor. Forecast variance at completion compares that estimate with the approved budget. Positive variance is remaining headroom. Negative variance is projected overrun.
Remaining budget after commitments deserves an early check because it ignores optimistic future assumptions. If actual spend plus committed cost has already crossed the approved budget, the risk is current, not just forecasted.
- Budget runway at current burn estimates how long the remaining budget lasts at the current actual-spend pace.
- Runway versus schedule compares that runway with remaining baseline days. A negative value means the remaining budget runs out first.
- CPI below 1 means earned value is lower than actual spend. SPI below 1 means earned value is lower than planned value for the status date.
- TCPI above 1 means remaining work must beat the baseline cost efficiency to finish inside the approved budget.
A within-budget result can still rest on weak inputs. Confirm that percent complete is measured consistently, planned spend is from the baseline, commitments are current, and warnings do not flag a date problem or actual spend above plan.
Technical Details:
Budget burn analysis combines a cost snapshot with a progress snapshot. The approved budget acts as the budget at completion, actual spend represents posted cost, and committed cost is added as a floor because a completion forecast below already spent or promised money would be unrealistic.
Elapsed schedule percent is calculated from whole days between the baseline start, status date, and baseline finish. The elapsed value is capped inside the schedule window for calculation purposes, while warnings still call out a status date before the start, a zero-day schedule, or a status date after the baseline finish.
Formula Core:
The main forecast methods estimate final spend, then the selected method is compared with the approved budget.
| Forecast method | Required input | Technical meaning |
|---|---|---|
| Time-based burn rate | Elapsed schedule percent greater than 0% | Actual spend is scaled from elapsed baseline time to the full baseline duration. |
| Percent-complete estimate | Percent complete greater than 0% | Actual spend is scaled by measured work progress. |
| Planned-spend burn ratio | Planned spend at status date greater than 0 | Actual spend is compared with planned value at the status date, then scaled to the total budget. |
| Manual remaining estimate | Manual uncommitted remaining estimate | Actual spend, committed cost, and the manual remaining estimate are added directly. |
Earned value indicators use the same baseline. Earned value is the approved budget multiplied by percent complete. Planned value comes from planned spend at the status date when entered; otherwise it is estimated from the elapsed schedule percent. CPI and SPI compare earned value with actual cost and planned value. TCPI to BAC compares remaining earned value with budget not yet posted as actual spend.
| Risk label | Boundary | Meaning |
|---|---|---|
| Commitments exceed budget | Remaining budget < 0 | Actual spend plus committed cost is already above the approved budget. |
| High overrun risk | Overrun percent >= overrun alert threshold | The selected final spend exceeds budget by at least the selected threshold. |
| Overrun watch | Forecast variance < 0 | The selected final spend is over budget but below the high-risk threshold. |
| Runway shortfall | Runway versus schedule < 0 days | Current actual-spend pace exhausts remaining budget before the baseline finish. |
| Reserve watch | Forecast variance <= reserve amount | The forecast is inside budget, but headroom is no larger than the selected reserve cushion. |
| Budget on track | No earlier rule applies | The selected forecast stays within budget, reserve, runway, and commitment checks. |
Runway uses actual spend per elapsed day, not forecast spend. When elapsed days are positive, actual spend divided by raw elapsed days becomes the current daily burn rate. Remaining budget divided by that burn rate gives runway days. The runway gap subtracts remaining baseline schedule days from runway days.
Rounding affects displayed money values, copied tables, and downloaded reports. Calculations keep numeric precision before formatting values as cents, whole units, or thousands.
Accuracy and Privacy Notes:
The results are budget-control estimates for planning and review, not audited accounting, financial advice, or a substitute for contract cost reporting.
- Use the same status date for actual spend, committed cost, planned spend, and percent complete.
- Percent complete is only reliable when it comes from accepted milestones, earned value rules, or measurable deliverables.
- Time-based forecasts can mislead when procurement, invoices, labor, or materials are front-loaded or back-loaded.
- Manual remaining estimates depend on current scope, staffing, procurement, and risk assumptions.
- Project cost figures are calculated in your browser; no upload is required for the budget calculation itself.
Worked Examples:
A $100,000 project has $40,000 actual spend, $8,000 committed cost, 50 elapsed days in a 100-day baseline, and 45% complete. Under Time-based burn rate, the selected forecast final spend is $80,000.00 because $40,000 divided by 50% elapsed equals $80,000.00. Forecast variance at completion is $20,000.00, and Budget runway at current burn is 65 days because the remaining budget after commitments is $52,000.00 and the actual burn rate is $800.00 per day.
The same project under Percent-complete estimate forecasts $88,888.89 because $40,000 divided by 45% progress implies a higher final spend than the time-based view. That difference is useful: the calendar says spend is below pace, but the progress estimate says the project has earned less work than the calendar would imply. CPI is 1.13 from $45,000 earned value divided by $40,000 actual spend, while SPI is 0.90 when planned value is $50,000.
A sharper warning appears when a $120,000 project has $78,000 actual spend, $10,000 committed cost, 50% elapsed schedule time, and Time-based burn rate selected. The selected forecast final spend is $156,000.00, so Forecast variance at completion is -$36,000.00 and the risk label becomes High overrun risk at a 5% threshold. The Runway versus schedule value is also negative because $32,000 remaining budget lasts about 21 days at a $1,560.00 daily burn rate while 50 baseline days remain.
A troubleshooting case occurs when the Status date is before Project start date. The Schedule Check reports Status before start, the time-based method is unavailable, and the warning list tells you that elapsed schedule time must be greater than 0% before that forecast can run. Fix the date or use a progress-based or manual forecast if the status snapshot is intentionally outside the baseline window.
FAQ:
Should committed cost be included before invoices arrive?
Yes, when the cost is already approved or contractually committed. Committed cost reduces Remaining budget after commitments and sets a floor under every completion forecast.
Which forecast method should I use first?
Use Time-based burn rate for an even-spend first pass, Percent-complete estimate when measured progress is stronger than the calendar, Planned-spend burn ratio when the baseline planned value is known, and Manual remaining estimate when the latest bottom-up estimate is more credible than pace-based math.
Why does a forecast method show unavailable?
A method becomes unavailable when its denominator is missing or zero. Time-based burn needs elapsed schedule percent above 0%, percent-complete needs progress above 0%, and planned-spend burn needs planned spend at the status date above 0.
Does CPI below 1 prove the project will overrun?
No. CPI below 1 means earned value is lower than actual spend at the status date. Check commitments, the selected forecast final spend, TCPI, percent complete quality, and planned value before treating it as a final overrun call.
Can I use a different currency?
Yes. Change Currency symbol in Advanced to a symbol or short code such as $, RM, EUR, or USD. The value is a display label only and does not perform exchange-rate conversion.
Glossary:
- BAC
- Budget at completion, represented by the approved total budget.
- Actual spend
- Posted or invoiced project cost as of the status date.
- Committed cost
- Approved but not yet posted obligations such as purchase orders, contractors, or vendor commitments.
- Planned value
- The amount of baseline budget expected to be earned or spent by the status date.
- CPI
- Cost performance index, calculated as earned value divided by actual spend.
- SPI
- Schedule performance index, calculated as earned value divided by planned value.
- TCPI
- To-complete performance index, showing the cost efficiency needed on remaining work to finish inside budget.
References:
- EVM Tutorial, NASA, updated 17 April 2026.
- Earned Value Management (EVM): Reference Guide for Project-Control Account Managers, NASA Technical Reports Server, 11 August 2015.
- Cost Estimating and Assessment Guide: Best Practices for Developing and Managing Program Costs, U.S. Government Accountability Office, 12 March 2020.
- Earned Value Management: From Data Analysis to Executive Action, Project Management Institute, 3 October 2002.
- TCPI, Project Management Institute, 23 October 2012.