The seven cash flow metrics every construction business should track are work-in-progress (WIP) over/under billings, retainage receivable, the cash conversion cycle, signed backlog, gross profit margin by job, days sales outstanding (DSO), and monthly burn rate. Together they answer the only question that matters between draws: do you have enough cash to make payroll and buy materials until the next payment clears? Construction is uniquely cash-hungry because you fund labor and materials weeks or months before an owner or GC releases a draw, and 5-10% of every invoice sits frozen as retainage until closeout. A job can be profitable and still bankrupt you if the timing is wrong. Watch these seven numbers weekly, and you will see a shortfall coming while you still have time to act — whether that means accelerating billings, slowing a start date, or bridging the gap with revenue-based funding.
Key takeaways
- Track seven metrics weekly: WIP over/under-billings, retainage receivable, cash conversion cycle, signed backlog, gross margin by job, DSO, and burn rate/runway.
- Under-billing is the fastest cash to recover — every under-billed dollar is work you've earned but never invoiced.
- Retainage (typically 5-10% per invoice) can stay frozen for months after you've paid all the associated costs; age it separately from regular AR.
- Construction cash conversion cycles commonly run 45-90+ days; the goal is to shorten the days you self-finance customers.
- Review gross margin per job at intervals (e.g., 25/50/75% complete) to catch estimating errors and scope creep while you can still act.
- Revenue-based / MCA funding approves on bank deposits and revenue (FICO 500+, from ~$10,000, 24-48h) — best for short timing gaps, never guaranteed.
- Financing buys time, not profitability: bridge a real timing gap, but fix chronic under-billing, slow collections, or eroding margins internally.
Why construction cash flow breaks even when jobs are profitable
Most trades and general contractors do not fail from lack of work. They fail from the timing mismatch between money going out and money coming in. You pay your crew every week or two, you pay suppliers on 30-day terms (often faster for a discount), and you carry the cost of mobilization, equipment, and rework. Meanwhile the owner pays on a draw schedule that can run 30, 60, or 90 days behind the work, and holds back retainage on top of that.
The result is a structural cash gap. On a growing book of business the gap gets wider, not narrower, because every new job pulls cash out before it pays cash back. This is why fast-growing contractors so often feel broke. The metrics below exist to make that gap visible and manageable instead of a monthly surprise. If you only ever look at your P&L, you are looking at profit, not cash — and in construction those two numbers can point in opposite directions for months at a time.
1. WIP: over-billings vs. under-billings
The work-in-progress schedule is the single most important report in a construction business, and most owners under-use it. WIP compares how much you have billed on each open job against how much you have actually earned (percent complete times contract value).
- Over-billed (billings exceed costs earned): you have collected ahead of the work. That cash is a short-term cushion — but it is borrowed from future draws, so do not treat it as profit.
- Under-billed (costs earned exceed billings): you have done work you have not invoiced. This is silent cash bleeding. Every dollar under-billed is a dollar you fronted and have not asked for yet.
Run a WIP schedule at least monthly, weekly during heavy seasons. Chronic under-billing is usually a billing-discipline problem, not a sales problem, and it is the fastest cash to recover: invoice what you have already earned.
2. Retainage receivable
Retainage (or retention) is the 5-10% of each progress payment the owner or GC withholds until the job is substantially or fully complete. On a large project that can be tens of thousands of dollars sitting frozen for months after you have already paid every cost associated with earning it.
Track total retainage receivable as its own line, separate from regular accounts receivable, and age it by expected release date. Two reasons: first, it tells you how much of your "receivables" you genuinely cannot spend yet. Second, aged retainage is one of the most common places cash quietly disappears — closeout paperwork stalls, punch lists drag, and nobody chases the release. Assign someone to pursue retainage the same way you pursue overdue invoices.
3. Cash conversion cycle
The cash conversion cycle measures how many days cash is tied up from the moment you spend it on labor and materials to the moment the corresponding payment lands in your account. In construction it runs long — 45 to 90+ days is common — because of draw schedules and retainage.
You do not need an accountant to feel it: it is the number of days you are effectively financing your customers. The goal is to shorten it. Levers include billing immediately at each milestone (not at month-end), negotiating deposits and faster draw schedules, taking supplier terms that match your inflows, and front-loading the schedule of values on early line items where legitimate. Every day you cut off the cycle is a day less of your own cash locked in the field.
4. Signed backlog
Backlog is the dollar value of contracted work you have not yet completed. It is your forward-looking cash pipeline. A healthy backlog gives you confidence to invest in crew and equipment; a thin or shrinking backlog is an early warning that a cash squeeze is coming two or three months out, long before it hits the bank account.
Track backlog in dollars and in months of coverage (backlog divided by average monthly revenue). Just as important, track its quality: are the margins real, are the customers creditworthy, and are the draw terms workable? A big backlog of thin-margin, slow-pay work can starve you faster than a smaller book of well-structured jobs.
5. Gross profit margin by job
Company-wide margin hides the truth. You need gross margin per job — contract revenue minus direct job costs (labor, materials, subs, equipment) — reviewed against your original estimate as the job runs. This is where estimating errors, scope creep, rework, and material price spikes show up while you can still do something about them.
A job trending below bid margin is a cash problem in the making: you will finish it having spent more than you priced, and the shortfall comes straight out of working capital. Reviewing margin at, say, 25%, 50%, and 75% complete lets you re-sequence, submit a change order, or tighten field spending before the loss is locked in.
6. Days sales outstanding (DSO)
DSO is the average number of days it takes to collect after you invoice. In construction, high DSO is the most common controllable cause of cash strain — and unlike draw schedules, a lot of it is within your power to fix. Slow collections mean you are financing owners and GCs out of your own pocket.
Bring DSO down with tighter billing discipline (invoice the day a milestone is hit), clean documentation so pay applications are not rejected, early-payment incentives, and firm, consistent follow-up on anything past terms. Watch the trend, not just the number: DSO creeping up over a few months is an early signal that a customer is struggling or your billing process has slipped.
7. Monthly burn rate and cash runway
Burn rate is your fixed and semi-fixed cash outflow in a month — payroll, overhead, equipment payments, insurance, rent — the money that leaves regardless of how much you collect. Divide your available cash (plus committed near-term inflows) by burn rate and you get your runway: how many months you can operate if collections stall.
Every contractor should know this number cold. It is what turns a seasonal slowdown or a single slow-paying owner from an existential threat into a manageable event. When runway drops below a comfortable buffer (many operators want at least one to two months of payroll in reserve), that is the signal to accelerate billings, defer discretionary spend, or line up a funding facility before the pinch — not during it.
Worked example: reading the metrics together
The metrics are most powerful read side by side. Here is an illustrative snapshot of a small commercial subcontractor mid-season. All figures are for example only.
| Metric | Current reading (for example) | What it signals |
|---|---|---|
| WIP position | $140,000 under-billed | Cash already spent but not yet invoiced — recover fast |
| Retainage receivable | $95,000, avg. 70 days to release | Real money, but frozen until closeout |
| Cash conversion cycle | 72 days | Over two months of self-financing per dollar |
| Signed backlog | $1.8M (about 4.5 months) | Healthy pipeline, but pulls cash forward as it starts |
| Gross margin by job | Two jobs 4-6 pts below bid | Margin erosion — investigate before completion |
| DSO | 58 days and rising | Collections slipping; tighten billing and follow-up |
| Burn / runway | ~3 weeks of payroll on hand | Thin runway against a busy start schedule |
Individually none of these is fatal. Together they tell a clear story: this contractor is profitable and growing, but the combination of under-billing, rising DSO, frozen retainage, and a thin runway against new job starts is a classic cash squeeze in the making. The fix is partly operational (invoice the $140k, chase the retainage, pull DSO back down) and partly a timing problem that may call for a working-capital bridge to cover payroll while those levers take effect.
Decision framework: when to bridge the gap with financing
Once the metrics reveal a gap, the question is whether to solve it internally or bring in outside cash. Revenue-based funding through an MCA / revenue-based marketplace approves on your bank deposits and revenue rather than credit — useful for contractors with strong cash flow but a temporary timing crunch. Underwriting leans on deposits and revenue, FICO 500+ is workable, funding amounts typically start around $10,000, and money can move in 24-48 hours. It is never guaranteed, and repayment comes out of future cash flow, so match it to the timing problem you are actually solving.
Works best when:
- You have a specific, short-duration gap — payroll and materials between a job start and its first draw, or while a large retainage release is pending.
- Your backlog and margins are solid, so future cash flow can comfortably absorb the repayment.
- You need speed — a draw slipped, a material order can't wait, and a bank line would take weeks you don't have.
- Bank or SBA credit isn't available fast enough because of time-in-business or credit history.
Avoid when:
- The real problem is chronic under-billing or slow collections — fix the billing process first; do not finance a leak.
- Margins are thin or eroding across the book; adding a repayment obligation on top of shrinking margin deepens the hole.
- You'd be using it to cover a structural loss rather than a timing gap. Financing buys time, not profitability.
- Your runway problem is really an overhead problem that cost discipline would solve.
The clean logic: choose to fix internally if the metrics point to billing discipline, collections, or overhead you control. Choose a revenue-based bridge if the work and margins are real and the only issue is the calendar gap between spending cash and collecting it. See our working capital guide for how to size a facility to the gap rather than over-borrowing.
Frequently asked questions
What is the most important cash flow metric for a construction business?
The WIP (work-in-progress) schedule, specifically your over/under-billings position. It reveals whether you have collected ahead of the work or done work you haven't invoiced yet. Chronic under-billing is the fastest-recoverable cash in most construction businesses — you're financing work you've already earned but never asked to be paid for.
Why is my construction business profitable but always short on cash?
Because profit and cash are different things in construction. You pay labor and materials weeks or months before draws are released, retainage freezes 5-10% of every invoice until closeout, and growth pulls cash out faster than it comes in. A job can be genuinely profitable while the timing of inflows and outflows leaves you unable to cover payroll. Tracking the cash conversion cycle, DSO, and runway makes that gap visible.
What is a healthy cash conversion cycle in construction?
It varies by trade and contract type, but 45-90 days is common because of draw schedules and retainage. There's no single 'right' number — what matters is the trend and shortening it where you can through faster milestone billing, deposits, negotiated draw terms, and supplier terms that match your inflows. Every day you cut is a day less of your own cash locked in the field.
How do I reduce days sales outstanding (DSO) on construction projects?
Invoice the day a milestone is hit rather than at month-end, keep pay-application documentation clean so applications aren't rejected, offer early-payment incentives where the math works, and follow up firmly and consistently on anything past terms. Watch the trend, not just the number — DSO creeping up over several months signals a struggling customer or a slipping billing process.
Should I use financing to cover a construction cash flow gap?
Use it for a specific, short-duration timing gap — covering payroll and materials between a job start and its first draw, or while a large retainage release is pending — when your backlog and margins are solid enough for future cash flow to absorb the repayment. Avoid it if the real problem is chronic under-billing, slow collections, or eroding margins; financing buys time, not profitability, so fix operational leaks first.
How does revenue-based funding work for contractors with bad credit?
Revenue-based funding and MCA marketplaces approve primarily on your bank deposits and revenue rather than your credit score, so FICO in the 500s is often workable. Amounts typically start around $10,000 and funding can move in 24-48 hours. It's never guaranteed, and repayment comes out of future cash flow, so it should be matched to a real timing gap backed by solid backlog and margins.
How much cash runway should a construction business keep?
Many operators aim for at least one to two months of payroll in reserve, calculated as available cash divided by monthly burn rate (payroll, overhead, equipment, insurance, rent). The right buffer depends on how seasonal your work is and how concentrated your customers are. When runway drops below your comfortable threshold, that's the signal to accelerate billings or line up a facility before the pinch, not during it.
What is retainage and how does it affect cash flow?
Retainage is the 5-10% of each progress payment an owner or GC withholds until the job is substantially or fully complete — sometimes tens of thousands of dollars frozen for months after you've already paid every cost of earning it. Track it separately from regular receivables and age it by expected release date, because aged retainage is a common place cash quietly disappears when closeout paperwork or punch lists stall.
