Building and running a 13-week cash forecast
Updated 16 October 2026
A 13-week cash forecast projects the bank balance at the end of each of the next 13 weeks. Each week has a row for money expected in, rows for money expected out, and an ending balance that carries into the next week. Thirteen weeks is one quarter. The forecast rolls: each week the owner drops the week just finished and adds a new week at the end, so the view always runs one quarter ahead. This page covers why profit and cash differ, how to lay out the forecast, how to place payments that come once a quarter or once a year, how to update it each week, and what it needs from the books.
Why profit and cash part ways
The profit and loss statement records sales when they are earned and costs when they are incurred. The bank records money when it moves. A business that sells on terms waits for its customers to pay. A business that holds stock pays for it before it sells. A business that is growing has more of both at once. Profit can rise in a quarter while the bank balance falls, and the forecast shows the bank side week by week.
A distributor sells $100,000 a month and its customers pay in 45 days, so about $150,000 sits in receivables at any time. Sales grow to $130,000 a month and the payment terms stay the same. Receivables rise to about $195,000. The extra $45,000 of sales has been earned and recorded as profit, and the cash for it has yet to arrive. The figures are an illustration.
The layout
The forecast has 13 columns, one per week, and a fixed set of rows. The first row is the opening cash balance, taken from reconciled bank accounts. The inflow rows come next: customer collections by week, then other receipts such as loan proceeds or tax refunds. The outflow rows follow: wages on their pay dates, rent, suppliers by their terms, loan payments, brand fees for a franchise, insurance, and tax payments on the dates a CPA sets. The last row is the ending balance, which becomes the next week's opening balance.
Mathnasium's 2026 Franchise Disclosure Document (FDD), the document a franchisor gives a buyer before a sale, reports 914 centers averaging $384,874 of sales, $79,182 of instructor wages, $49,098 of rent and $66,883 of brand charges. Spread over 52 weeks, the average center takes in about $7,401 a week. Wages run about $3,045 per two-week pay period. Rent is about $4,092 a month, and brand charges about $5,574 a month. Over one 13-week quarter, those averages put about $96,219 in and pay about $19,796 of wages, $12,275 of rent and $16,721 of brand charges. A Mathnasium owner replaces those averages with the center's own dates and amounts.
Payments that come once a quarter or once a year
Weekly and monthly costs repeat, so each one goes in the same row every period. Larger payments that come less often cause most surprises: insurance premiums, annual software renewals, equipment purchases, loan balloon payments, bonuses and tax payments. List every such payment for the next 12 months once, with its date and amount, and copy each into the forecast when its week comes into view. Tax payment dates and amounts come from a CPA.
A business opens the quarter with $30,000 and adds a net $1,000 a week from operations. By week eight the balance is $38,000. In week nine an $18,000 insurance premium and a $9,000 annual software renewal fall due together, and the balance drops to $12,000. The owner's minimum balance is $20,000, so week nine is $8,000 short. The forecast shows this in week one, eight weeks ahead. The figures are an illustration.
The weekly update
Once a week, the owner or the CFO enters what happened in the week just finished, compares it with what the forecast said, and rolls the forecast forward one week. The comparison matters most. A collection that came in late, a supplier bill paid early, or a payroll that ran over shows up as a difference between forecast and actual. Each difference either moves a later week or changes an assumption. The forecast then goes to the weekly leadership meeting, and a named person owns the figure.
The forecast for week four expected $42,000 of collections. The bank shows $35,500. The $6,500 gap traces to two customers who paid one week late. The owner moves $6,500 into week five and lengthens the collection assumption for those two customers from 30 days to 37 days for the rest of the forecast. The figures are an illustration.
What the forecast needs from the books
The forecast takes its opening balance, its collections and its bills from the books. The opening balance needs reconciled bank accounts. The collection rows need an accurate receivables aging, which lists every unpaid customer invoice by how long it has been outstanding. The bill rows need an accurate payables list. When the books are behind, each of those inputs is a guess. A monthly close on a fixed date keeps the forecast anchored to recorded figures. The month-end close checklist lists the steps.
A business has $180,000 of receivables. Of that, $108,000 is under 30 days old, $45,000 is 31 to 60 days old, and $27,000 is more than 90 days old. The forecast places the $108,000 in the next four to six weeks and the $45,000 in the following weeks. The $27,000 goes into the forecast only for customers who have agreed a payment date. The figures are an illustration.
What this means for an owner
A 13-week forecast shows the bank balance at the end of each week of the coming quarter. It starts from reconciled cash, places every inflow and outflow on its expected week, and rolls forward one week at a time. Payments that come once a quarter or once a year go on a 12-month list and enter the forecast as their weeks arrive. Each week the forecast is compared with the bank, and the differences change later weeks. The forecast relies on closed books for its opening balance, receivables and bills.
Cash forecasting at Averan
Averan Advisors builds 13-week forecasts from the books it closes, updates them each week and reviews them with the owner. The fractional CFO service page describes the forecasting work and the budgets that sit beside it.
The EOS finance resources hub covers the books, the monthly close, the Scorecard numbers and the cash forecast in a company that runs on the Entrepreneurial Operating System (EOS).
If you want this done for you
What happens next
Reading about it and having it done are different things. Here is exactly what happens if you want the second one.
- The call takes thirty minutesYou describe the business and where the numbers are letting you down. We give you an expert view of your situation, and what we would start with. There is no pitch deck.
- We look at the fileYou give us read access to the books as they are. We come back with what is wrong, what it will take to fix, and whether the answer is bookkeeping, controller work, or something else.
- We send a written scope and a priceIt lists what we do each month, what you get, the date it lands and the fee. We agree it before anything starts, and it does not change unless you agree.
- We take over the books and close the first monthWe set up access and systems and enter the opening balances. The first close lands on the date in the scope, and every one after it does too.