Finance

What is working capital in construction?

Working capital is a contractor's current assets minus current liabilities, the short-term cushion that pays crews and suppliers while waiting on owners, and one of the first numbers sureties and banks check.

Two construction professionals review paper plans beside a tablet at a jobsite workbench.
Plan reviews connect field conditions, drawings, and the next decisions on a job. AI-generated illustration.

Working capital is the money a contractor could free up in the next year, minus what it owes in the next year. The formula is simple: current assets minus current liabilities. Current assets include cash, accounts receivable, retainage receivable, and underbillings. Current liabilities include accounts payable, retainage payable, overbillings, accrued payroll, and the current portion of loans.

In construction, working capital is the cushion between paying for work and getting paid for it. Crews are paid every payday. Suppliers want their terms honored. Owners pay on their own cycle, and often hold retainage until closeout. The gap is funded by working capital or by debt.

How working capital works in practice

Say a site contractor's year-end balance sheet shows:

Example: working capital calculation (illustrative)
Current assetsAmountCurrent liabilitiesAmount
Cash$420,000Accounts payable$510,000
Accounts receivable$880,000Retainage payable$90,000
Retainage receivable$260,000Overbillings$210,000
Underbillings$70,000Line of credit and current debt$300,000
Total$1,630,000Total$1,110,000

Working capital is $1,630,000 minus $1,110,000, or $520,000. That is the number the contractor's surety and bank will start from. Sureties often adjust it, for example by discounting receivables that are old or in dispute, so the figure they use can be lower than the one on the statement.

Notice what sits on each side. Retainage receivable is a current asset even though some of it may not be collected for months, and overbillings are a current liability even though no check is written for them. Both are why a contractor's working capital can look different from its bank balance.

Why working capital matters for contractors

  • Bonding: sureties use working capital, along with equity, to set single-job and aggregate bond capacity.
  • Growth: taking on more work requires more cash tied up in payroll and materials before the first pay app clears. Growth eats working capital.
  • Survival: a contractor with thin working capital can be profitable on paper and still miss payroll when one owner pays late.
  • Bank lines: lenders often set covenants on working capital or the current ratio (current assets divided by current liabilities).

Ways contractors improve working capital

  1. Bill on time and chase receivables weekly. A pay app sent five days late is five days of working capital you funded.
  2. Bill retainage the day it is releasable, and push closeout documents early.
  3. Keep billings aligned with progress. Heavy underbillings tie up cash; heavy overbillings hide future cost.
  4. Retain earnings in the business instead of distributing all profit.
  5. Move long-term equipment purchases to long-term financing rather than paying cash from operations.
  6. Negotiate payment terms with owners and suppliers that match your cash cycle.

Common mistakes

Counting old receivables at full value, ignoring overbillings as a liability, and treating a line of credit as working capital are the classic ones. Drawing on the line raises cash and current debt equally, so working capital does not change. Another common one is growing revenue faster than working capital can support, which shows up as slow pay to subs right before it shows up anywhere else.

Related terms

See operating cash flow, work in progress, and overbilling. Smart Business Automator's receivables and WIP views help keep billing current, which is the fastest lever on working capital.

Frequently asked questions

How do you calculate working capital?

Subtract current liabilities from current assets using the balance sheet. For contractors, include retainage and over and under billings in the right columns.

Why do sureties care about working capital?

It shows whether a contractor can fund jobs through slow pay and problems without running out of cash, which is the main risk a surety guarantees against.

Does a line of credit count as working capital?

An undrawn line is not working capital, though lenders and sureties consider it as available liquidity. Money drawn on the line adds cash but also adds a current liability.

What is a good current ratio for a contractor?

There is no single number. Sureties and lenders set their own expectations based on the contractor's size and work type. Ask your surety agent what they look for.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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