13-week cash flow forecast template: the direct method, the revolver line that most templates get wrong, and a weekly variance loop

When liquidity is tight, the first document a lender, a turnaround adviser or a board asks for is thirteen weeks of cash, by week, direct method. Thirteen weeks because it is a quarter, short enough to forecast receipt by receipt and long enough to show whether the company runs out. This page is how that model is built, which part templates usually get wrong, and how the weekly loop works once it is running.

Not investment, tax or legal advice.

Why direct, not indirect

An indirect cash flow starts from profit and adjusts for non-cash items and working capital movements. It is right for a three-statement model and useless for a cash call, because it cannot tell you which Thursday the payroll clears. A direct forecast lists actual receipts and actual payments in the week they hit the bank: collections, cash sales, asset sales, drawdowns on one side; supplier payments, payroll, rent, VAT and payroll taxes, tax instalments, capex, debt service on the other.

The part most templates get wrong: the opening balances

New sales in week 3 do not become cash in week 3. Neither does the receivables balance you start with. A forecast that only models new business misses most of the cash in the first month.

So the model needs two curves:

• Collection curve: what share of the opening receivables balance arrives in week 1, week 2, week 3 and so on, plus the terms on which new sales convert.
• Payment curve: the same for the opening payables balance and for new purchases.

Those two curves unwind the balance sheet you start with into the weeks ahead. Get them from the aged debtor and creditor listings, not from average DSO.

The revolver line, done properly

Most spreadsheets model a revolving facility as a plug: cash goes negative, so draw the difference. That is wrong in two ways. It ignores the minimum cash balance the company wants to hold, and it ignores the facility limit, which means the model can quietly show a draw larger than the facility and a company that looks solvent when it is not.

The correct order inside each week is: opening cash, plus receipts, less disbursements, less revolver interest, gives net cash before financing. Then the draw or repayment is whatever holds closing cash at or above the minimum, capped at the remaining availability under the limit. Then closing cash, revolver balance, availability and headroom. If the cap binds, the week is flagged: that is the week the facility is exhausted, and it is the single most important output in the file.

From those weeks come the headline numbers a lender asks for: lowest cash and the week it happens, peak revolver balance, minimum availability, and how many weeks the facility runs out.

The working capital bridge

A cash forecast built from receipts and payments should still reconcile to the accounting story. A bridge from EBITDA to operating cash through the change in receivables, payables and inventory does that, with closing balances derived from the direct forecast and DSO and DPO at period end. If the bridge does not tie, one of the curves is wrong.

The Monday loop

A 13-week forecast is not a document, it is a routine. Every Monday: paste last week's actual receipts, disbursements and closing cash; the model shows the variance per line, the cumulative drift and the forecast accuracy for that week; then the forecast rolls forward one week. Accuracy is a number you can improve, and after a month of it the curves stop being guesses.

Where the workbook fits

The 13-Week Direct Cash Flow Forecast is those sheets: Inputs (week 1 date, opening cash, minimum cash, revolver limit and opening balance and rate, opening receivables, payables and inventory, and the collection and payment curves), Receipts, Disbursements, Forecast (the weekly build with the revolver logic and the headline block), WC bridge, Variance and a Guide sheet. The revolver logic, balances and headline figures were recomputed in Python from the same inputs and matched cell by cell before it went on sale. Live formulas, no macros, no locked cells, Excel and Google Sheets. $39 single user, team and consultancy licences above.

It is not for a monthly indirect cash flow inside a three-statement model: the DCF model does that. For the runway question rather than the liquidity question, the runway and burn model and the free runway calculator are the shorter route.

Last updated 23 September 2026.