A 13-week cash forecast is a rolling, week-by-week view of the cash your business expects to receive and pay over the next quarter.
Why 13 weeks
Thirteen weeks is one quarter. It’s far enough out to see payroll cycles, quarterly taxes, loan payments, and slow-paying customers coming. It’s close enough that your estimates stay honest.
A monthly P&L tells you whether you made money. A 13-week forecast tells you when money reaches or leaves the bank. A profitable business can still run short of cash, and this is how you see it coming.
What goes in it
- Beginning cash for each week: what’s in the bank, plus available credit if you track it separately.
- Cash in: customer collections, by the week you expect them to arrive. Base them on when customers actually pay.
- Cash out: payroll, vendors and materials, rent and fixed costs, taxes, debt payments, and planned purchases.
- Ending cash for each week, compared with the minimum balance you want to keep.
Six mistakes to avoid
- Building it from the P&L. Start from the bank account and actual payment timing.
- Using invoice terms as collection dates. A customer on net 30 who pays in 52 days belongs in week 8.
- Forgetting the lumpy payments. Quarterly taxes, insurance, annual software, bonuses, and loan balloons cause most surprises.
- Too much detail. Twenty well-chosen lines beat two hundred. The forecast tracks timing. The books keep the detail.
- Building it once. A forecast you don’t update decays within weeks.
- No minimum cash floor. Without one, a low week is just a number. With one, it’s a decision.
The weekly rhythm
The forecast is only half the tool. The other half is the 30 minutes each week where you use it.
- Update what happened. Replace last week’s estimates with actuals.
- Recheck what’s coming. Adjust collections and commitments with what you know today.
- Find the tight weeks. Focus on the lowest projected balances.
- Make the next decision. Chase a receivable, time a purchase, or line up credit while you still have options.
- Roll it forward. Add a new week so you always see a quarter ahead.
A rough forecast you update every week beats a perfect one you build once.
Who should own it
Your bookkeeper or controller can prepare the numbers. The owner, or whoever owns cash decisions, should run the weekly review. Preparing the forecast is accounting work. Using it is leadership work. The value comes from the decisions, so the person who makes them needs to be in the room.
Get the tools
For a worked example with real numbers, read the 13-week cash flow guide ↗. To start your own, download the free 13-Week Cash MAP ↗: an Excel template, a quick start guide, and a weekly review worksheet.
Questions owners ask
What is a 13-week cash flow forecast?
A rolling, week-by-week projection of the cash a business expects to receive and pay over the next quarter. Each week, actual results replace estimates and a new week is added.
Why use 13 weeks for a cash forecast?
Thirteen weeks is one quarter. It is long enough to see payroll cycles, quarterly taxes, and slow collections, and short enough for estimates to stay reliable.
How long does a 13-week cash forecast take to update?
Once it is built, a simple forecast usually takes under an hour a week to update, plus a 30-minute review to make decisions from it.
Who should own the 13-week cash forecast?
A bookkeeper or controller can prepare it. The owner, or whoever makes cash decisions, should run the weekly review, because the value comes from the decisions.
