13-Week Cash-Flow Forecast for Construction Companies: Step-by-Step Guide

A construction company can have signed contracts, active projects and healthy expected margins while still facing a shortage of cash. The difficulty is often timing: payroll, materials, equipment and subcontractors may need to be paid weeks before a progress payment arrives. A 13-week construction cash-flow forecast helps make that timing visible before it becomes an emergency.

This guide explains how to build a rolling forecast, what construction-specific items to include and how to use the results when planning expenses or considering business financing.

What Is a 13-Week Cash-Flow Forecast?

A 13-week cash-flow forecast is a week-by-week estimate of the money expected to enter and leave a business over approximately three months. It begins with the company’s available cash, adds expected receipts, subtracts expected payments and calculates the projected closing balance for every week.

Thirteen weeks is long enough to expose upcoming pressure from payroll cycles, supplier bills, tax payments and project schedules, but short enough to update using reasonably dependable information. Unlike a profit-and-loss statement, the forecast concentrates on the date cash is expected to move.

For example, revenue may be recorded when work is completed, but the related cash might not arrive until an invoice is approved and paid. The forecast places the receipt in the week the money is realistically expected—not simply the week it is invoiced.

Why Construction Companies Need a Short-Term Forecast

Construction businesses often carry costs before collecting the revenue connected to them. Materials may require deposits, crews must be paid on schedule and subcontractors may have contractual payment dates. Meanwhile, customer payments can depend on inspections, change-order approval, lender draws or a general contractor’s payment cycle.

Retainage can create additional pressure because a portion of earned revenue may remain unavailable until a project or milestone is completed. Several profitable projects can therefore increase the company’s need for working capital rather than immediately increasing available cash.

A forecast helps a contractor:

• Identify the week in which cash may fall below a safe operating level.
• Coordinate material purchases with expected project receipts.
• Prepare for payroll, subcontractor and equipment obligations.
• Model the effect of a delayed draw or disputed change order.
• Decide whether a new project can be started without straining existing work.
• Estimate the amount and timing of a possible funding need.

If the underlying causes are unclear, first review common construction cash-flow problems and how to address them.

Information to Collect Before Building the Forecast

The forecast is only as useful as the assumptions behind it. Start with current records rather than broad monthly averages.

Opening cash balance

Use the amount of cash that is genuinely available for operations. Exclude restricted funds, customer deposits that cannot legally or contractually be used elsewhere and balances reserved for taxes or other specific obligations.

Expected cash receipts

List each significant receipt separately and assign it to the week in which payment is realistically expected. Possible inflows include:

• Progress payments and approved draws
• Customer deposits
• Accounts-receivable collections
• Approved change-order payments
• Retainage releases
• Equipment-sale proceeds
• Other operating income

Confirm invoice status with the project manager or accounts-receivable team. A submitted pay application should not automatically be treated as cash arriving in the next week.

Expected cash payments

Schedule payments for the week they are due or expected to clear. Include:

• Employee payroll, payroll taxes and benefits
• Subcontractor payments
• Materials, supplier deposits and freight
• Equipment purchases, rentals, fuel and repairs
• Insurance, bonding and permits
• Rent, utilities, software and professional services
• Debt or financing payments
• Sales, income and other tax obligations
• Owner draws and other planned distributions

Separate committed costs from optional spending. That distinction becomes important if the forecast reveals a shortfall.

How to Build a 13-Week Construction Cash-Flow Forecast

Step 1: Create one column or row for every week

Begin with the current week and add the following 12 weeks. Use consistent ending dates, such as every Friday or Sunday. A simple forecast can be built in a spreadsheet with categories down the left and weeks across the top. The vertical layout below is easier to view on a website:

The figures above are illustrative only. Continue the same structure through Week 13 using your company’s actual expected receipts and payments.

Step 2: Enter the opening cash position

The first week begins with today’s usable cash balance. Each following week begins with the previous week’s projected closing balance. This connection allows one delayed payment to flow through the remainder of the forecast.

Step 3: Forecast receipts by project and payment date

Estimate collections project by project. Consider the customer’s payment history, the status of required documentation, pending inspections and whether the invoice is disputed. If timing is uncertain, use the more conservative date or create separate base and delayed-payment scenarios.

Step 4: Schedule direct project costs

Enter payroll, materials, rentals and subcontractor payments according to the project schedule and contractual due dates. Avoid spreading a known invoice evenly across a month. Cash-flow forecasting should reflect when the payment will actually leave the account.

Step 5: Add overhead and less-frequent obligations

Include office payroll, insurance, vehicle payments, rent, tax deposits, licenses and other overhead. Quarterly or annual expenses are easily missed when a forecast relies only on the previous month’s bank activity.

Step 6: Calculate weekly net cash flow

Use these basic calculations:

Weekly net cash flow = Total cash inflows − Total cash outflows

Closing cash balance = Opening cash balance + Weekly net cash flow

The lowest projected closing balance is particularly important. It shows the point of greatest cash pressure, even if the business finishes Week 13 with a positive balance.

Step 7: Compare the result with a minimum cash target

A positive balance is not necessarily a comfortable balance. Establish a minimum operating threshold based on essential payroll, project commitments and unexpected expenses. Highlight every week in which closing cash falls below that level.

Step 8: Update the forecast every week

Replace estimates with actual figures, investigate the differences and add a new Week 13. This creates a rolling forecast that continuously looks three months ahead.

Worked Construction Cash-Flow Example

Assume a contractor begins with $85,000 of available cash and expects a $75,000 progress payment in Week 3. Before that payment arrives, the company must meet two payroll cycles, purchase materials and pay equipment rental charges. The forecast shows the balance declining to $40,000 in Week 2.

A second major material order is due in Week 4. Even though the Week 3 payment increases cash, the Week 4 commitments reduce the projected balance to $22,000. If the contractor’s minimum safe balance is $35,000, the forecast reveals a $13,000 gap in Week 4.

Management can now investigate the shortfall in advance. Possible responses might include confirming the progress-payment date, negotiating a staged material delivery, accelerating a valid receivable, rescheduling nonessential spending or comparing appropriate financing options. The right response depends on the contracts, costs and overall condition of the business.

Businesses that want to measure the broader timing difference between operating assets and liabilities can also use the working capital gap formula.

Common Construction Forecasting Mistakes

Using invoice dates instead of expected payment dates

An invoice does not provide cash until it is paid. Base the forecast on realistic collection timing and update it when approval or payment status changes.

Counting unapproved change orders as certain revenue

Work may be completed before a change order is formally approved. Track potential revenue separately until the amount and payment are sufficiently dependable.

Ignoring retainage

Record only the portion of a payment expected to be received during the 13-week period. Keep withheld retainage separate and use a realistic release date.

Forecasting revenue without the related costs

A new project can produce substantial revenue while consuming cash first. Add the materials, labor, mobilization and subcontractor costs required to earn each expected receipt.

Assuming every customer pays on time

Build assumptions around actual payment behavior. For important or uncertain receipts, compare an expected scenario with a delayed scenario.

Failing to reconcile the forecast

Every week, compare forecast receipts and payments with actual bank activity. Repeated differences can reveal unrealistic assumptions, missing expenses or weak collection processes.

How to Use the Completed Forecast

The forecast should support decisions, not simply report a number. Review it with project managers or other employees responsible for billing, purchasing and scheduling.

• Prioritize collections: Focus follow-up on approved invoices that materially affect upcoming balances.
• Coordinate purchasing: Align large orders with project schedules and confirmed cash availability.
• Protect payroll: Treat payroll and payroll taxes as scheduled obligations, not adjustable estimates.
• Test new work: Add the expected receipts and upfront costs of a proposed project before committing resources.
• Run scenarios: Test what happens if a large payment is delayed by two or four weeks or if material costs increase.
• Act early: A shortage identified eight weeks ahead generally provides more options than one discovered two days before payroll.

For a broader overview of financing considerations within the industry, visit the construction business funding guide.

When Business Funding May Help

Financing does not repair an unprofitable contract, uncontrolled costs or a permanent gap between revenue and expenses. It may, however, help an otherwise viable construction business manage a temporary and clearly identified timing difference.

Depending on eligibility, purpose and available offers, a contractor might consider working capital financing, a business line of credit, equipment financing or another commercial funding structure. Each option has different costs, terms, payment requirements and qualification standards.

Before applying, use the forecast to answer four questions:

1. What is causing the projected shortage?
2. What is the maximum expected cash gap?
3. In which week will funds be needed?
4. What expected cash flow would support repayment?

Submitting an application does not guarantee approval. Financing availability and terms depend on the provider’s review and eligibility requirements.

Frequently Asked Questions

What is a 13-week construction cash-flow forecast?

It is a weekly projection of expected cash receipts, payments and closing balances over the next 13 weeks. Construction companies can use it to identify timing gaps created by payroll, materials, subcontractor bills, progress payments and retainage.

Why use 13 weeks instead of a yearly forecast?

A yearly forecast supports long-term planning, but its weekly details become less dependable further into the future. A rolling 13-week forecast focuses on near-term payment timing while still providing enough warning to address potential shortages.

How often should a construction cash-flow forecast be updated?

Update it at least weekly. Replace the completed week with actual results, revise payment assumptions and add a new final week so the forecast always extends 13 weeks forward.

Should retainage be included?

Yes, but only schedule retainage as an inflow when its release is realistically expected. Do not treat withheld retainage as currently available operating cash.

How should delayed progress payments be handled?

Move the receipt to the revised expected week and allow the resulting lower balance to carry through the remaining forecast. For uncertain payments, compare a base case with a delayed-payment scenario.

Can a forecast show how much financing a contractor needs?

It can help estimate the size and timing of a temporary cash gap, but the funding decision should also consider minimum reserves, financing costs, repayment capacity and unexpected changes. Eligibility and available amounts depend on the provider and applicant.

This article is for general educational purposes and is not financial, legal, accounting or tax advice. Forecasts are estimates, and financing products, eligibility requirements and terms vary by provider and applicant.