FP&A
What Is a 13-Week Cash Flow Forecast?
A 13-week cash flow forecast is a rolling weekly projection of cash in and out for the next 13 weeks, the CFO's primary tactical tool for staying solvent. It surfaces cash gaps 4 to 8 weeks ahead, before they become emergencies. It runs alongside the 12-month strategic plan, and the two answer different questions.
The 13-week cash flow forecast is the CFO's primary tactical tool: a rolling weekly projection of cash in and out for the next 13 weeks. It surfaces cash gaps 4 to 8 weeks ahead, before they become emergencies. Run alongside your 12-month strategic plan; the two answer different questions.
Structure
One spreadsheet, 13 weekly columns. Rows are line items grouped:
- Receipts: DTC card settlement, Amazon payouts, wholesale Accounts Receivable (AR) collections, financing draws
- Operating outflows: supplier purchase order (PO) deposits and balances, freight, duty, payroll, rent, software, marketing
- Non-operating outflows: debt service, capital expenditures (CapEx), tax payments, owner distributions
- Net cash flow: receipts minus all outflows
- Ending cash balance: prior week ending plus this week's net
Why 13 weeks
One full fiscal quarter (12 weeks) plus a buffer week. Long enough to surface cash gaps before they're emergencies. Short enough that line-item granularity is feasible. Beyond 13 weeks, weekly noise overwhelms the signal. Use the 12-month plan for anything longer.
Update cadence
Weekly. Every Monday: drop week 1 (now actuals), shift weeks 2 to 13 forward, add a new week 13 at the back. Variance commentary against the prior forecast is the CFO's tactical signal of the week.
The most common mistake
Treating the 13-week as a one-time exercise. The value is in the weekly update plus variance commentary. Skipped weeks let drift accumulate, and by the time you look again, cash is already in trouble. The forecast is only useful if it's alive.
Frequently Asked Questions
why exactly 13 weeks?
One full quarter plus a buffer week. Long enough to catch gaps, short enough for line-item granularity.
how often do i actually update this thing?
Weekly, every Monday. Drop week 1 into actuals, shift forward, add a new week 13.
13-week forecast vs 12-month forecast, which do i need?
Both, in parallel. 13-week tactical + weekly. 12-month strategic + monthly.
Related Terms
- What is a driver-based forecast?
- What is cash runway?
- What is a rolling forecast?
- What is variance analysis?
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