Free calculator
Cash Runway Calculator
Estimate how long your cash would last if monthly receipts and payments stayed as you enter them — both to the minimum balance you want to keep and to zero — with a simple month-by-month table and an optional downside case. For payment-by-payment planning, use the 13-week cash-flow forecast.
How long could my available cash last under these assumptions?
Money in the bank you can actually use, not invoices still unpaid
The buffer you never want to go below; 0 if none
Money actually collected from customers and other sources
Everything paid: costs, wages, owner withdrawals, loan repayments, tax
e.g. if a large customer leaves or pays late
Nothing is saved or sent anywhere.
Result
Enter your numbers
The formulas
Monthly net cash movement = cash received − cash paidMonthly burn = cash paid − cash received (when payments are higher)Months to minimum ≈ (cash now − minimum balance) ÷ monthly burnMonths to zero ≈ cash now ÷ monthly burnWorked example
You have 50,000 and want to keep at least 10,000. Each month you collect 20,000 and pay out 30,000, so cash falls by 10,000 a month. That is (50,000 − 10,000) ÷ 10,000 = 4 months to the minimum and 50,000 ÷ 10,000 = 5 months to zero.
In a downside case where receipts drop to 15,000, the burn is 15,000 a month: about 2.7 months to the minimum and 3.3 to zero.
Plan the dates with the forecast
This calculator uses one figure for every month. Real cash arrives and leaves on particular days, and a quarterly bill can empty the account before the average says it will. The 13-week cash-flow forecast lists each expected receipt and payment by week, so you can see the lowest point and act before it.
Common questions
What counts as cash received and cash paid?
Only money that actually moves through the bank. Received: customer payments collected, loans drawn, owner money put in. Paid: suppliers, wages, rent, loan repayments, tax payments, equipment bought, and what you take out for yourself. Unpaid invoices, depreciation and profit figures do not belong here.
How do I avoid counting things twice?
Enter each payment once. If your pay is already in “payments” as owner withdrawals, do not also deduct it from receipts. If a loan repayment includes interest, enter the whole repayment once, not the interest again as a cost.
Why does the table show a different month from the estimate?
The estimate (for example “about 3.5 months”) assumes cash falls evenly through the month. The table shows balances at the end of each month, so the first month-end at or below the line is month 4.
My receipts cover my payments. Am I safe?
Cash does not decline under constant monthly figures, but real months are uneven. A quarterly tax bill or a customer paying late can still create a shortfall. Plan payment dates with the 13-week cash-flow forecast.
What should the downside scenario be?
A realistic bad case you can name: a large customer leaving, slower payments, or a cost rising. Enter the monthly receipts and payments you would expect, and compare the two runways.