13-Week Cash Flow Forecast Template for SaaS

How the 13-week cash flow template works

Every line in the forecast is a payment with a date, and each date lands in a Monday-to-Sunday week. That is the whole difference from a monthly model: it does not matter that rent and payroll are monthly costs, it matters which week the money leaves.

• Subscription collections come from what you bill each month. The share paid by card arrives a couple of days after the billing date (when the payout reaches your bank). The share paid on invoice arrives after the payment terms, so last month's invoices show up in this month's weeks.
• Annual invoices are entered one by one, because one renewal can be larger than a month of subscriptions. Cash lands in the invoice week plus the terms; anything that falls after week 13 is reported separately.
• Payroll is the monthly cost including employer taxes and benefits, split into pay runs: every other Friday, the 15th and last day of the month, or the last day only. The template lists the weeks with a pay run.
• Rent, software, vendor bills and one-off payments land on their own day or week. Payment processing is a percentage of customer collections in the week they arrive.

Closing cash for a week is the opening cash plus receipts minus disbursements, and it becomes the next week's opening cash.

Worked example: the default forecast

A SaaS company starts the week of Oct 26, 2026 with $600,000 in the bank and wants to keep at least $400,000. It bills $60,000 a month on the 1st, growing 2% a month; 60% pays by card (cash 2 days later) and the rest on net 30 invoices. Payroll is $110,000 a month, paid twice a month. Two annual renewals are due, plus hosting bills, an insurance renewal, year-end bonuses and a loan repayment.

Week 1 shows how the timing works. The invoices billed on October 1 are due on October 31 (net 30), so $24,000 arrives. The November 1 bill is paid by card on November 3, which is week 2. Payroll for the second half of October ($55,000) and November rent ($6,000, due on Sunday, November 1) both fall in week 1, with $600 of processing on the collections. Net cash flow is −$37,600 and the week closes at $562,400.

Over the quarter the company collects $220,154 and pays out $487,466. Cash first drops below the $400,000 minimum in week 10 (week of Dec 28), when the December 31 payroll, January rent, a hosting bill and the $15,000 loan repayment all leave in the same week ($89,548 out against $61,934 in), and it ends at $332,688. A monthly view would show the same ending balance and miss the week it happened. The second renewal ($24,000, net 45) is invoiced in week 8 but paid on Jan 28, after the window, which is why it does not help: moving its terms to net 30 would bring it inside.

Closing a week: variance and the rolling 13 weeks

Now four weeks have passed. Set Weeks closed to 4 and type the actual totals: receipts $20,000, $36,000, $0, $5,000; disbursements $62,000, $21,000, $55,000, $8,000.

One invoice was paid $4,000 short in week 1 and $5,000 arrived in week 4 that was not in the forecast, so receipts are ahead overall; payments ran $400 over in week 1 and $900 under in week 2. Cash after week 4 is $515,000, $1,500 ahead of plan. The template carries that balance forward, keeps the forecast lines for the weeks still to come, and extends the window to week 17. Week 13 now closes at $334,188 instead of $332,688, and the new low point is $294,182 in week 17 (week of Feb 15): the rolling window shows the February payroll, which the first forecast could not see yet.

Weekly cash flow vs the 36-month model

The two answer different questions. A monthly model, like the SaaS budget template or a full SaaS financial model, starts from revenue drivers, hiring and costs and tells you whether the plan works over one to three years: when you break even, how much runway the plan leaves, how much to raise. The 13-week cash flow starts from the bank balance and actual payment dates and tells you whether there is enough cash in each week of the next quarter. For the same receipts and payments month by month over a full year, use the 12-month cash flow forecast template.

• Use the monthly model to set the budget, decide on hires and price changes, and show investors the path. Runway in months comes from here; the runway calculator gives the quick version.
• Use the 13-week cash flow when cash is tight, before a fundraise closes, when a few large annual invoices drive collections, or when a lender asks for one. It catches the week where payroll and a big bill coincide, which a monthly total averages away.
• Use both once a month: the first month of the monthly model should roughly equal the first four or five weeks of the weekly forecast. If they disagree, one of them has the timing or an amount wrong.

Adlega builds the monthly side for you: a 36-month driver-based model with revenue, headcount, P&L and cash, scenarios, and actuals that update the forecast. Start the 36-month model in Adlega and keep this template for the next 13 weeks.

Download the Excel version

The Excel template has the same defaults and the same math as live formulas: an Inputs sheet for the balances, billing, payroll and payment lists, a Forecast sheet with the 13-week table and the low point, a Rolling sheet where you enter each week's actual receipts and disbursements to get the variance and the next 13 weeks, and a Schedule sheet that lists every billing, payroll and rent date so you can check where each number comes from. No email needed. For the monthly picture, see cash flow forecasting for SaaS and burn rate and runway; before revenue, managing cash flow in a pre-revenue SaaS company covers what to watch.