Free 13-Week Cash Flow Forecast Calculator

Q: Should I enter revenue or cash received?

Enter cash you expect to land in the bank that week. Put immediate cash sales on the first line and collections of open invoices on the customer payments line, and avoid counting the same sale twice.

Q: Can I use it for a Canadian business?

Yes. Select CAD as the currency. The calculator does not convert between USD and CAD, so enter all amounts in the currency you select.

Use this free 13-week cash flow forecast calculator to project your business cash balance week by week for the next quarter. Enter your beginning cash, expected receipts and expected payments — the calculator shows weekly net cash flow, ending balances, weeks with a potential cash shortage and an estimated cash runway. It works in USD or CAD, needs no signup, and your numbers never leave your browser.

How to use this forecast

Choose your currency and enter the cash in your bank accounts today.
Enter the cash you expect to receive and expect to pay in each of the next 13 weeks. Use positive numbers only — the calculator adds receipts and subtracts payments.
Use Copy → to repeat a week-1 amount across all 13 weeks, then adjust individual weeks.
Review flagged weeks, the chart and the summary. Download a CSV or print the report.

Your numbers stay in your browser. Nothing you type is sent to AccoTiva or saved.

1. Starting position

Currency

Beginning cash balance *Total cleared cash in business bank accounts today. Use a minus sign for an overdraft.

Minimum cash bufferOptional. Weeks below this amount are flagged.

Week 1 starts onOptional. Labels each week with a date.

2. Weekly receipts and payments

Scroll sideways to see all 13 weeks.

3. Forecast results

Total cash inflows—

Total cash outflows—

Net cash flow (13 weeks)—

Ending cash, week 13—

Lowest cash balance—

Weeks below zero—

Weeks below buffer—

Estimated cash runway—

Bars show forecast ending cash each week (red = below zero, amber = below your buffer). The dashed line is your minimum cash buffer.

Disclaimer: This calculator produces estimates based only on the numbers you enter. It is not accounting, tax, legal or lending advice, and actual results will differ. Runway is estimated from your average weekly net cash flow and assumes that pattern continues.

Need help managing your business finances?

A forecast is only as reliable as the books behind it. AccoTiva keeps your accounts reconciled and can build a rolling 13-week forecast from your real bank data.

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What is a 13-week cash flow forecast?

A 13-week cash flow forecast is a rolling, week-by-week projection of the cash you expect to receive and pay over roughly one quarter. Unlike a profit and loss statement, it tracks when cash actually moves — so it shows whether you can cover rent, supplier bills and loan payments in a specific week, not just whether the business is profitable on paper.

How the calculator works

Total cash inflows = cash sales + customer payments + other cash receipts for the week.
Total cash outflows = operating expenses + vendor payments + loan payments + other cash payments.
Net cash flow = total inflows − total outflows.
Ending cash = beginning cash + net cash flow. Each week’s ending cash becomes the next week’s beginning cash.
Potential shortage = any week where ending cash is below zero (or below the minimum buffer you set).
Estimated runway = if cash goes negative, the first week it does; otherwise, beginning cash ÷ average weekly net cash outflow, assuming the 13-week pattern continues.

Tips for a more reliable forecast

Start from reconciled bank balances, not the balance your accounting software shows before reconciliation.
Forecast customer payments from your accounts receivable aging and realistic collection dates — not invoice dates.
Use your accounts payable list, recurring payment schedule and loan statements for outflows.
Include irregular items: annual renewals, insurance, equipment, owner draws and tax payments your accountant has estimated.
Update the forecast weekly: replace the week that just ended with actual numbers and add a new week 13.

For a step-by-step method, read our guide on how to build a 13-week cash flow forecast. If your books are behind, a forecast built on them will be unreliable — our catch-up bookkeeping and monthly bookkeeping services fix that first.

Frequently asked questions

Is my financial information saved or sent anywhere?

No. All calculations run in your browser. AccoTiva does not receive or store the numbers you enter. Refreshing the page clears them, so download the CSV if you want to keep a copy.

Should I enter revenue or cash received?

Enter cash you expect to land in the bank that week. Card sales usually settle within a few days; invoiced sales arrive when customers pay. Put immediate cash sales on the first line and collections of open invoices on the customer payments line, and avoid counting the same sale twice.

Can I use it for a Canadian business?

Yes. Select CAD as the currency. The math is the same in either currency; the calculator does not convert between USD and CAD, so enter all amounts in the currency you select.

What minimum cash buffer should I use?

It depends on your business. A common starting point is enough cash to cover one or two weeks of essential payments such as payroll, rent and critical suppliers. Set it to match your own risk tolerance.