What is a 13-week cash flow forecast?
When cash is tight, monthly forecasts aren't enough. The 13-week cash flow is the weekly, near-term view that finance teams and turnaround specialists use to see trouble coming.
Skip the math — the free 13 week cash flow forecast template runs this from your own figures.
Open the free calculator →A weekly view of the next quarter
A 13-week cash flow forecast projects the cash coming in and going out of a business each week for the next quarter. Instead of monthly buckets, it works week by week, so it captures the timing of payroll runs, supplier payments, and customer receipts.
The output is a running weekly cash balance: start with this week's cash, add expected receipts, subtract expected payments, and carry the closing balance into next week — for thirteen weeks.
Why 13 weeks
Thirteen weeks is one quarter — long enough to see a cash problem forming and act on it, but short enough that your assumptions about who pays when are still reliable. Beyond a quarter, weekly estimates get too speculative to trust.
It's become the standard short-term cash tool, especially in tight-cash situations and restructurings, precisely because it hits that sweet spot between foresight and accuracy.
What it catches that monthly forecasts miss
A monthly forecast can show a healthy month overall while hiding a week in the middle where cash briefly hits zero — for example, when payroll and a big supplier payment land before a large receipt arrives.
The weekly resolution of the 13-week forecast surfaces exactly these short, sharp gaps, giving you time to chase a receipt, delay a payment, or arrange cover before the crunch.
How to build one
List your expected cash receipts by week (based on real invoice due dates and payment habits, not just sales), then your expected payments by week (payroll, rent, suppliers, loans, taxes). Compute net cash and a running balance for each of the 13 weeks.
Update it weekly — roll it forward one week, compare last week's forecast to what actually happened, and adjust. A 13-week forecast is a living document, not a one-off.
Use it to act early
The value isn't the spreadsheet — it's the decisions it triggers. A projected dip in week 7 is a prompt to accelerate collections, negotiate terms, or line up funding now, while you still have options.
The free calculator below gives you your weekly runway from your cash and weekly flows, and the full 13-week forecast maps every week so a shortfall never takes you by surprise.
Questions
Who uses a 13-week cash flow forecast?
It's a staple for finance teams, CFOs, and especially turnaround and restructuring professionals, but it's just as valuable for any small business with tight or variable cash. Any business where the timing of payments matters — which is most of them — benefits from seeing cash weekly rather than only monthly.
How often should I update it?
Weekly. The whole point is a rolling view: each week you drop the week that just finished, add a new week 13 at the far end, and compare your forecast to what actually happened so your estimates keep improving. A 13-week forecast that's updated once and forgotten loses almost all its value.