Burn Rate Calculator
Free burn rate calculator: enter starting cash, current cash, and months elapsed to get net burn, estimated gross burn, and the runway your burn implies.
Bank balance at the start of the measurement period.
Months between the two balances.
Used to estimate gross burn (total spend). Enter 0 if pre-revenue.
Results
Net burn rate
$30,000
Cash consumed per month, after revenue.
- Gross burn rate (est.)Net burn plus average monthly revenue - total monthly spend.
- $45,000
- Implied runwayCurrent cash divided by net burn, assuming burn holds steady.
- 12.7 months
You burned $120,000 over 4 months - $30,000 of net burn per month. At that pace, your remaining $380,000 lasts about 12.7 months.
Free and instant - nothing is stored or sent. Estimates for planning purposes, not accounting, tax, or investment advice.
Burn rate is the speed at which a business consumes cash. You do not need a full accounting system to measure it - two bank balances and a calendar are enough. Compare where cash stood a few months ago with where it stands today, and the burn rate falls out.
This calculator computes net burn (cash consumed per month, after revenue), estimates gross burn (total monthly spend) when you add average monthly revenue, and translates the result into implied runway on your remaining balance.
Net burn vs. gross burn
Net burn is the cash the business actually loses each month: (starting cash − current cash) ÷ months elapsed. It nets revenue against spending, which is why it is the number runway is built on.
Gross burn is total monthly spending before revenue - net burn plus monthly revenue. Investors watch both: net burn says how long you can live, gross burn says how big the machine is that revenue must eventually cover.
With the defaults - $500,000 falling to $380,000 over four months with $15,000 of monthly revenue - net burn is $30,000 per month and estimated gross burn is $45,000 per month.
Why measuring from bank balances works
Measuring burn from actual bank balances captures everything: payroll, taxes, annual subscriptions, the equipment purchase nobody logged. Accounting-based burn figures often miss cash timing; the bank account never does.
The trade-off is noise. A single big receivable landing (or missing) can distort a short window, so measure over at least three months - and exclude one-time events like a funding round from the starting balance, or the burn figure will be meaningless.
How to interpret the result
The implied runway - current cash ÷ net burn - is the headline. A runway of 12–18 months is typically targeted between funding rounds; under six months means fundraising or cost action needs to start immediately, because both take longer than people expect.
Watch the direction of burn, not just the level. Burn that grows faster than revenue means the business is scaling its costs ahead of its model. Recompute monthly and chart the trend.
Frequently asked questions
What is the difference between gross burn and net burn?
Gross burn is total cash spent per month. Net burn is cash spent minus cash collected - the actual monthly decline in the bank balance. Runway is always computed on net burn. A company spending $45,000 with $15,000 of revenue has $45,000 gross burn but $30,000 net burn.
What is a good burn rate for a startup?
There is no universal number - burn is judged against runway and progress. A commonly cited discipline is keeping enough cash for 12–18 months of net burn and ensuring burn grows slower than revenue. Burn without corresponding growth is the pattern that alarms investors.
Why does my burn rate jump around month to month?
Cash timing: quarterly tax payments, annual software renewals, three-payroll months, and lumpy collections all move individual months. That is why this calculator measures across several months - the average smooths the noise a single month can inject.
Should a funding round count in the burn calculation?
No. Measure burn between two balances that exclude financing events, or start the measurement the month after the round lands. Including an equity injection makes burn look negative and hides the real operating trend.
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