Start with timing
Revenue on the income statement is not the same as cash collected. Enter expected receipts based on invoice and payment behavior, not the month work is performed.
Free business finance tool
13-Week Cash Flow Calculator for Small Business
Model weekly collections and disbursements, see the lowest projected cash point, and pressure-test what happens when receipts slow or expenses increase.
No account required Educational, not individualized advice
Forecast assumptions
Use expected cash timing, not accounting revenue. All recurring values are weekly.
Cash grows in this scenario
Ending cash
$166,000
Lowest week
$107,000
13-week change
$66,000
Projected weekly cash
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| Week | Receipts | Disbursements | Ending cash |
|---|---|---|---|
| 1 | $50,000 | $43,000 | $107,000 |
| 2 | $50,000 | $43,000 | $114,000 |
| 3 | $50,000 | $43,000 | $121,000 |
| 4 | $50,000 | $43,000 | $128,000 |
| 5 | $50,000 | $43,000 | $135,000 |
| 6 | $50,000 | $68,000 | $117,000 |
| 7 | $50,000 | $43,000 | $124,000 |
| 8 | $50,000 | $43,000 | $131,000 |
| 9 | $50,000 | $43,000 | $138,000 |
| 10 | $50,000 | $43,000 | $145,000 |
| 11 | $50,000 | $43,000 | $152,000 |
| 12 | $50,000 | $43,000 | $159,000 |
| 13 | $50,000 | $43,000 | $166,000 |
How to use the result
The forecast is a management conversation, not a prediction contest
Use the model to expose timing, assumptions, and decisions. Update actual cash and collections every week; do not leave the original forecast untouched for a quarter.
Separate committed and optional cash
Payroll, debt, taxes, and signed vendor commitments behave differently from discretionary hiring, equipment, owner payments, and growth spending.
Watch the low point
Ending cash matters, but the lowest weekly point determines whether payroll, debt, or investment decisions create a short-term liquidity problem.
Base, downside, and action scenarios
A useful forecast shows what management can change before the low point arrives.
| Scenario | Collections assumption | Expense assumption | Management use |
|---|---|---|---|
| Base | Most likely payment timing | Current operating plan | Normal weekly cash management |
| Downside | Receipts arrive later or below plan | Committed costs continue | Define trigger points and protective actions |
| Growth | Signed work and realistic pipeline | Hiring and delivery capacity added | Test whether growth can fund itself |
| Action | Base receipts | Specific change such as delayed hire or faster collections | Compare a decision before approval |
Take the working file with you
Take the 13-week model into your operating meeting
Get the editable weekly forecast structure, assumption notes, scenario prompts, and a cash-review meeting agenda.
Frequently asked questions
What is a 13-week cash flow forecast?
It is a weekly projection of cash receipts and disbursements over roughly one quarter. The short interval helps management see collection timing, payroll, debt, taxes, vendor payments, and upcoming decisions before they affect the bank balance.
Should I use revenue or collections?
Use expected cash receipts. Start from invoices, contracts, payment terms, and actual customer behavior. Revenue may be useful as a cross-check, but the forecast must reflect when money is expected to reach the account.
How often should the forecast be updated?
Update opening cash and near-term receipts and payments at least weekly when liquidity matters. Compare actual results with the prior forecast so assumptions improve instead of simply replacing the old numbers.
What expenses belong in the forecast?
Include payroll, benefits, contractors, rent, software, vendors, debt, taxes, owner payments, equipment, and other known cash events. Separate committed items from discretionary choices so management can see what can be changed.
Why is this different from a profit-and-loss statement?
The P&L measures financial performance under the accounting method. The cash forecast models timing. Receivables, payables, debt principal, asset purchases, and owner activity can move cash differently from reported profit.
When should a business get CFO help with cash flow?
Consider help when collections, payroll, debt, entities, locations, or growth decisions create material timing risk; when the forecast is not updated; or when management cannot explain why cash differs from profit.