13 weeks is the only forecast that matters in a downturn

When revenue slows, most founders find out from their bank balance. By then the options are few and expensive.

A 13-week cash forecast changes that. It’s a simple weekly view of money coming in and going out, updated every Friday, and it gives you three months of warning instead of three days.

Why 13 weeks?

It’s long enough to see a problem coming and short enough to be accurate. You know your payroll dates, your rent, your big invoices. You can forecast them week by week with confidence.

A monthly forecast tells you whether you’ll make money. A weekly forecast tells you whether you’ll make payroll.

How to build one

1. Start with today’s bank balance.
2. List every expected receipt by week: invoices, card payouts, loans.
3. List every payment by week: payroll, rent, suppliers, tax.
4. Roll the balance forward and highlight any week below your minimum.
5. Every Friday, replace the forecast week with what actually happened.

After four weeks, compare the forecast with reality. The gaps tell you where your assumptions are wrong, and that’s the most useful part.