THE CONSTRUCTION CASH CONVERSION CYCLE
The cash conversion cycle measures how long it takes for a dollar of cost spent to come back as a dollar of cash received. For commercial subcontractors, the realistic cycle is 60–110 days — not the 30–45 days most owners assume. The math: days payable outstanding (typically 30–45 on vendor terms) minus days cash conversion (typically 90–155 from work performed to ACH receipt, factoring in pay app timing plus retention). Subs that don’t calculate their actual cycle operate against optimistic cash assumptions and hit the working capital wall during growth phases when the cycle stretches further still.
A 75-day cash conversion cycle means every dollar of work performed today turns into cash 75 days from now. The bank account knows this. The P&L doesn’t.
WHAT THE NUMBER ACTUALLY MEASURES
The cash conversion cycle (CCC) measures the time elapsed between cash going out for project costs and cash coming back from project receivables. For a commercial subcontractor, the calculation is:
CCC = Days Cash Conversion − Days Payable Outstanding
Days Cash Conversion = the average elapsed time from when work is performed to when cash arrives in the operating account. Days Payable Outstanding = the average elapsed time from when a cost is incurred to when the corresponding payable is settled. The difference is the structural cash gap the business has to finance out of working capital.
For a healthy commercial sub: Days Cash Conversion typically runs 90–155 days (60–90 days pay app cycle plus retention compounding). Days Payable Outstanding typically runs 30–45 days (standard vendor net 30 plus a few days of slip). Result: a 60–110 day cash conversion cycle that has to be financed somewhere.
WHERE THE TIME ACCUMULATES
WORK-TO-INVOICE LAG
Work performed mid-month bills on the following month’s pay app, submitted 5–10 days into the next month. Average lag from work performance to invoice submission: 18–28 days. Most subs accept this as a fixed constraint, but tightening the billing cadence (weekly or bi-weekly pay app structures where the contract allows) can cut this to 8–15 days — pulling 10–15 days out of the cash conversion cycle on its own.
INVOICE-TO-CASH LAG
From pay app submission to ACH receipt in the operating account. For commercial GC clients on private commercial work: 45–75 days standard. For public sector clients: 60–120 days standard. Project close-out invoices can take 120+ days. This is the largest single component of the cycle and most subs accept it as fixed — but tighter pay app documentation, prompt-pay statute enforcement on public work, and proactive AR management can pull 10–20 days out per project.
RETENTION HOLD CYCLE
5–10% of every pay app held until substantial completion of the entire project (often months past your scope completion). For a sub whose work finishes in month 8 of a 14-month project, retention sits another 6–8 months past last billable activity. When averaged across active projects, retention extends the effective cash conversion cycle by 20–40 days beyond the basic pay-app timing.
A $5M SUB WALKED THROUGH
Consider a commercial electrical sub at $5M annual revenue, mixed across 60% private commercial GC work and 40% public sector work. Average pay app cycle: 65 days. Average retention hold: 30 days (effective average across active projects). Average work-to-invoice lag: 22 days. Days Cash Conversion = 22 + 65 + 30 = 117 days.
Vendor terms run mostly net 30 with some net 45 on specialty equipment, average DPO = 38 days. Cash conversion cycle = 117 − 38 = 79 days.
What this means in practice: every dollar of project cost spent today won’t come back as cash for 79 days on average. To support $5M of annual revenue at this cycle length, the business needs roughly $1.1M of working capital tied up at any moment just to bridge the cycle. Growing to $7M would require another $440K of working capital just for the cycle bridge — before any other growth investment.
This is why profitable contractors hit cash crises during growth. The cycle bridge requirement scales linearly with revenue while profit accumulates slowly. Growth without addressing the cycle is what closes businesses.
WHERE THE DAYS COME OUT
- Tighten work-to-invoice lag — Weekly or bi-weekly pay app structures where contracts allow. Faster T&M invoicing (within 5 days of work completion). Can pull 10–15 days from the cycle.
- Tighten invoice-to-cash lag — Proper pay app documentation (complete on first submission, no kickback for missing items). Prompt-pay statute enforcement on public work. Stored materials provisions on gear-heavy scopes. Can pull 10–20 days per project.
- Manage retention proactively — Track retention release dates by project, follow up at substantial completion, push for early release on completed scopes where contracts allow. Can pull 15–30 days from the retention component.
- Optimize DPO without damaging vendor relationships — Negotiate net 45 or net 60 with major suppliers in exchange for committed volume. Cycle-aware payment scheduling. Can extend DPO by 10–15 days.
- Mobilization-loaded SOV structure — Real mobilization costs recovered in weeks 1–4 instead of absorbed into working capital. Functionally reduces the effective cash conversion gap on every new project.
A 79-day cycle compressed to 55 days through systematic application of these tactics reduces working capital requirement by roughly 30%. On the $5M sub above, that’s $330K of operating cash freed up — without changing revenue, margin, or overhead.
THE CYCLE IS MANAGED, NOT ACCEPTED
The CFOS framework treats cash conversion cycle as a managed metric, not a fixed constraint. Every active project has cycle data tracked: actual days work-to-invoice, actual days invoice-to-cash, retention release schedule, vendor terms applied. The aggregate cycle gets reported monthly alongside the standard financial statements.
When the cycle creeps longer (a new client paying slower than expected, a project entering retention hold), the change becomes visible immediately and the working capital impact gets modeled in the 13-week cash forecast. Growth decisions get made against real cycle data instead of assumed cash availability. The business runs against actual financial reality instead of optimistic assumptions about how fast money will come back.
FREQUENTLY ASKED
