Free Burn Rate Calculator: Net Burn, Gross Burn, Cash Runway

What Is Project Burn Rate?

Burn rate in project management means how fast cash leaves a business or a budget, usually measured monthly. Gross burn counts everything going out. Net burn subtracts what comes in. Divide your balance by net burn, and you get cash runway, the number of months before the money is gone.

The term came out of venture capital, where it tracks how fast a startup consumes the money it raised. Project teams borrowed it for a different question. On a capital project, the funding is already approved, so nobody asks when the money runs out. They ask whether what remains will cover the work that remains.

Same arithmetic. Different benchmark.

How to Use This Project Burn Rate Calculator

The burn rate calculator runs two modes. Company cash burn works as a cash runway calculator, returning runway and a zero-cash date from your bank balance. Project budget burn returns a forecast final cost from your approved budget.

Here is how to calculate company cash burn.

1. Select your currency from the dropdown.
2. Enter your current cash balance.
3. Enter average monthly cash out, then average monthly cash in.
4. Press Calculate burn rate.

For project budget burn, the steps are slightly different.

1. Switch to the Project budget burn tab.
2. Enter your total approved budget and spend to date.
3. Enter months elapsed and months remaining.
4. Enter work complete as a percentage of the physical works.
5. Press Calculate burn rate.

Two inputs decide whether the project answer is any good.

• Spend to date must include accruals, work completed but not yet certified, and change orders you expect to approve. Leave those out, and the burn rate flatters you.
• Work complete means physical progress against the works. Not time elapsed, and not budget spent. Either of those makes the comparison circular.

The chart carries the answer. It plots budget burned, time elapsed, and physical progress against a typical S-curve, so you can see which of the three is out of step. Open Advanced options for burn growth rate, team size, contingency held, and committed spend.

The calculator returns estimates from the figures you enter. Treat the output as a planning input rather than financial advice, and check it against your own cost report before acting on it.

How to Calculate Burn Rate Manually

Net burn rate is monthly cash out minus monthly cash in. The burn rate formula comes in three parts.

• Gross burn rate = total monthly cash out
• Net burn rate = gross burn − monthly cash in
• Cash runway = cash on hand ÷ net burn rate

Cash out means money that actually left the account. That covers payroll, rent, software, subcontractors, insurance, and tax. Cash in means money you banked, not money you invoiced. Non-cash items like depreciation and amortization are excluded from both.

If bank statements are easier to reach than your expense ledger, the period method gets you there from two balances.

Monthly burn rate = (cash at start − cash at end) ÷ number of months

Use a full month as your period. That is what makes it a monthly burn rate rather than a snapshot. Shorter windows get distorted by payment timing, and quarterly figures hide the month a problem started.

Step by step

Step 1: Add up everything that leaves the account in a normal month. That is gross burn.

Step 2: Subtract the cash you actually collect. Collected, not invoiced. Use a rolling three-month average so one lumpy receipt does not distort it.

Step 3: Divide the balance by net burn for runway in months.

Step 4: Convert those months into a calendar date.

Most people skip step four, and it changes behavior more than the other three combined. A firm holding $600,000, spending $95,000 a month and collecting $35,000 has a net burn of $60,000 and ten months of runway. Ten months is an abstraction. A date is a deadline. The burn rate calculator above runs all four steps and returns the date.

Gross Burn Rate vs Net Burn Rate

Gross burn is everything leaving the account. Net burn is that same figure minus the cash coming in. Cash burn rate gets used loosely for either, which is why people argue about numbers that were never the same number.

Track both. Gross burn is what the operation costs if income stopped tomorrow. Net burn tells you how much time you have.

What Is a Good Burn Budget Rate?

There is no good burn budget rate in dollars. The figure only means something next to two things. How much time is left, and how much work is done.

On a project, a healthy burn rate tracks the S-curve and stays close to physical progress. Spend slightly ahead of time elapsed is normal mid-build. Spend ahead of progress is not normal at any stage, and it is the reading worth escalating.

For an organization watching cash, the convention is runway in months. Most boards want 18 to 24 months of cover. Below 12, the question stops being operational.

How Do You Calculate Construction Burn Rate?

Divide spend to date by months elapsed. Multiply that by the months remaining, add spend to date, and you have a straight-line forecast final cost.

• Project burn rate = spend to date ÷ months elapsed
• Forecast final cost = spend to date + (burn rate × months remaining)

Project burn rate and budget burn rate describe the same figure. That forecast is crude on purpose. It tells you what happens if nothing changes. A proper construction cost forecast accounts for the shape of remaining works, committed contracts, and known changes. But when the crude version says you are over budget, the sophisticated one has to explain why not.

Why burn rate alone will mislead you

Construction spend does not run flat. It follows an S-curve, slow through early works and procurement, steep through the main build, and tapering through commissioning.

So a project that has burned 45% of its budget in 45% of its program looks balanced and may be well behind. In month nine of twenty, it should be past halfway on spend.

Burn rate analysis on a project means reading all three together. The pairing to worry about is spend running ahead of progress, because you are paying for work you have not received.

That is the earliest clean signal of a cost overrun. Bent Flyvbjerg's research in What You Should Know About Megaprojects, and Why found nine out of ten run over budget. That rate has held roughly constant across 70 years of data. Forecasting is rarely where it goes wrong. Noticing is.

The earned value version

Earned value management (EVM) compares the value of completed work against what you have spent to get it.

• Earned value (EV) = budget at completion × % complete
• Cost performance index (CPI) = EV ÷ actual cost
• Estimate at completion = budget at completion ÷ CPI

A CPI below 1.0 means you are spending faster than you are earning value. In project management, burn rate is sometimes inverted and quoted as actual cost divided by earned value, the PMP convention, where anything above 1.0 signals overspend. Check which one your organization uses before quoting a figure, because the two move in opposite directions.

Your burn rate is only as good as your cost data

Every formula above assumes spend to date is complete. It usually is not.

Exclude accruals, unapproved change orders (variations in the UK and Australia), or work finished but not yet certified, and the rate you calculate is flattering. Your forecast final cost is wrong by the same margin. Most budget surprises are capture failures, not forecasting failures.

How Do You Reduce Project Burn Rate?

Test commitments before they are contracted, and draw contingency only against risks you have actually retired. Those two levers do more than anything else, and both close as the job progresses.

1. Reforecasting changes nothing. Rescoping, resequencing or a targeted contingency drawdown does. A drawdown recorded against no particular risk is just a smaller contingency.
2. Uncommitted budget is the only part you still control. Once work is contracted, that money is effectively spent.
3. Challenge allowances and provisional sums early. They are the softest numbers in the budget while the design is still moving.
4. Shorten the reporting cycle.

That last one matters more than its length suggests. A figure calculated three weeks after month-end describes a situation you can no longer influence. Teams running live cost reporting catch drift while there is still budget to redirect.

Keeping Your Burn Rate Current

Recalculate burn rate monthly, against your cost report. The formulas take a minute. Assembling trustworthy inputs takes most teams three weeks, by which point the forecast describes last month.

Fix the input problem, not the formula. Mastt's construction project cost management software holds budgets, commitments, payments, and forecasts in one place, so burn rate moves as the data moves.

The project cost management guide covers where this metric sits alongside cash flow, contingency, and earned value.