Enter the figures and calculate the result
Enter Current cash balance, Revenue for this period, and Total expenses for this period. Choose the matching option in Period for revenue & expenses below: Monthly, Quarterly, Annual, Weekly, or Custom period length…. The result shows gross burn rate and net burn rate per month, plus estimated cash runway in months.
How to use the calculator
- Enter a cash balance, revenue, and expenses of 0 or more.
- Choose a period and use revenue and expenses for that same period. If you choose Custom period length…, enter Days per period as plain integer digits, with a minimum of 1. Values such as
01and1.0are rejected. - Select Currency symbol if needed. It labels the amounts; it does not convert them.
- Click Calculate burn rate. Invalid or blank values show an error and no result.
- Use Copy result for the plain-text summary or Download result (.txt) to download it. If copying fails, select and copy the result manually. Click Reset to clear the entered values and hide the result.
How the result is calculated
The calculator first converts the selected period to a monthly amount:
Monthly amount = Amount × Periods per year ÷ 12- Periods per year are 12 for monthly, 4 for quarterly, 1 for annual, 52 for weekly, and
365.25 ÷ days per periodfor a custom period.
It then applies these formulas:
Gross burn = Monthly expensesNet burn = Monthly expenses − Monthly revenueCash runway (months) = Cash balance ÷ Net burn
How to read the result
The result displays Gross burn rate (per month), Net burn rate (per month), and Cash runway. The assumptions table includes the entered values, selected period, normalization factor, monthly revenue and expenses, burn rates, and runway. Money uses two decimal places; other calculated figures can display up to four.
When revenue exceeds expenses, the displayed net burn uses the absolute amount and adds (net positive). When net burn is zero or negative, Cash runway shows Not burning cash (revenue covers or exceeds expenses). The downloaded text preserves the signed net burn amount.
Limits and assumptions
- The calculator uses the figures you enter. It does not fetch live bank balances, accounting data, live rates, or external financial records.
- The currency selection changes the displayed symbol only; it does not convert values or apply exchange rates.
- Runway assumes revenue and expenses remain constant. It does not model seasonality, one-time charges, financing events, or future changes in spending or revenue.
- The fields ask for cash revenue collected and cash operating expenses. The calculator does not detect or enforce an accounting basis.
- Validation rejects blank, non-numeric, non-finite, or negative cash, revenue, and expense values. Custom days must use plain integer digits and be at least 1; forms such as
01and1.0are rejected. - Displayed and exported numbers are formatted to limited decimal places.
Privacy & Security
The calculator computes from its cash, revenue, expense, period, and currency fields locally in your browser. It does not send those calculator inputs to a server.
Frequently Asked Questions
What is the difference between gross burn and net burn?
Gross burn is your total monthly operating expenses, with no offset for revenue. Net burn is gross burn minus revenue collected in the same period, so it reflects the actual rate your cash balance is shrinking. If revenue exceeds expenses, net burn is negative, meaning cash is growing rather than depleting.
How is cash runway calculated?
Cash runway is calculated as cash balance divided by net burn rate, expressed in months. It estimates how many months of operation remain at the current net burn rate before cash reaches zero, assuming revenue and expenses stay constant. If net burn is zero or negative, runway is treated as not applicable since cash is not being depleted.
Does this tool fetch my actual bank balance or accounting data?
No. It only calculates from the cash balance, revenue, and expenses you type in. It does not connect to a bank, accounting system, or fetch live financial records - everything is calculated locally in your browser and nothing is uploaded.
What period should I use for revenue and expenses?
Enter revenue and expenses for the same period you choose (monthly, quarterly, annual, weekly, or a custom number of days). The calculator normalizes whatever period you pick to a monthly figure before computing burn rate and runway, so results are always expressed per month.
Is this a substitute for financial or accounting advice?
No. This tool performs a transparent arithmetic calculation on the figures you provide. It is not financial, accounting, tax, or investment advice, and it does not account for seasonality, one-time items, financing events, or changes in spending or revenue over time.