How Much Cash Should a Construction Company Have on Hand?

Key Takeaways

Most construction companies should maintain 10–30% of annual revenue in cash reserves — the same target Anders recommends across industries
The challenge isn’t the target. It’s the timing — milestone-based billing makes cash harder to predict than in most other industries
Most construction companies belong closer to 20–30% given project variability, subcontractor obligations, and client concentration risk
A line of credit equal to your reserve target is an essential backup — secured before it’s needed
Three separate accounts — operating, reserve, and tax — keep the reserve protected and the picture clear

Construction companies don’t struggle with cash because they lack revenue. They struggle because cash in construction doesn’t move on a predictable schedule — it moves when milestones are verified, lien waivers are cleared, and contract terms permit billing. That gap between when work happens and when cash arrives is what makes the reserve harder to build and hold versus most other industries.

One factor that doesn’t get enough attention in this conversation is the mix of work. Many construction companies aren’t purely project-based; they also run a service arm with smaller, repeatable jobs that bill and collect much faster. That mix matters. Larger projects build backlog and drive revenue, but they come with milestone billing delays and heavier subcontractor exposure. Service work tends to turn quickly, generating more consistent cash inflow. The companies that intentionally balance both often see less volatility in their cash position, even if their reserve target doesn’t change on paper. Without that mix, the business is far more dependent on the timing of a handful of milestone payments, which increases the pressure on the reserve to absorb delays.

The target Anders recommends is the same across industries. The construction-specific challenge is maintaining it. For a broader look at the framework, see How Much Cash Should a Business Have?

What Is the Right Cash Reserve for a Construction Company?

We always recommend that construction companies strive for a cash reserve of 10–30% of annual revenue. At 10%, that covers roughly two months of operating expenses. At 30%, closer to six months.

As a general starting framework:

10%: Stable businesses with predictable revenue and short cash cycles
20%: Moderate growth, some variability in timing or project mix
30%: High growth, inconsistent revenue, significant subcontractor volume, or elevated risk

Most construction companies belong toward the higher end of that range. Milestone-based revenue, subcontractor payment obligations, and project timing variability create cash exposure that a thinner reserve can’t absorb — and unlike most industries, cash doesn’t arrive on a consistent monthly cycle that makes the reserve easy to replenish.

How to Calculate Your Construction Cash Reserve

In most industries, AR days are relatively stable and predictable. In construction, they’re not. A project might pay in 30 days; another might run past 90 depending on milestone timing, lien waiver requirements, and owner approval processes. That variability is what makes the standard cash reserve formula produce a larger number for construction companies than owners typically expect — and why most contractors who calculate it using average payment cycles end up with a target that’s too low.

The formula is straightforward.

Step 1: Annual Revenue ÷ 365 = Average Daily Revenue

Step 2: Accounts Receivable Days – Accounts Payable Days = Cash Usage (or the amount of time you need to have your bills (AP) covered before your cash comes back in the door (AR))

Step 3: Daily Revenue × Cash Gap = Ideal Cash Reserve

The key is what goes into the AR days figure. We build it from milestone-specific timing rather than averages, meaning we account for the actual billing schedule on each active contract rather than a blended rate across all clients. AP days on subcontractor payments are short by contract, typically seven days or less once an owner payment is received, which widens the gap further. For more on the metrics that keep this calculation accurate over time, see cash flow metrics as an ongoing check on your balance sheet.

Does Your Construction Company Need 10% or 30%?

Of all the factors that push a construction company toward the higher end of the range, one is underweighted more than any other: the subcontractor dynamic. Most contractors adjust their reserve target for growth plans or project size. Few adjust for the AP pressure that payment terms and pay-when-paid provisions create. Once an owner payment arrives, most contracts require the sub payment to turn around within seven days. Cash that looks available on Monday can be obligated by Friday, across multiple projects simultaneously. The formula doesn’t account for that velocity, which means the reserve target MUST.

For a deeper look at how milestone billing creates cash timing risk in construction, our Virtual CFOs cover the mechanics in detail.

Factors that push toward 30%:

Irregular pipeline with variable project start dates and milestone timing
High client concentration — more than 10% of revenue from a single client means one delayed payment compresses the entire cash position
Large subcontractor volume with significant pay-when-paid obligations that move fast once triggered
Percent complete estimates, underbilling, and unresolved change orders that make cash flow projections less reliable
Seasonal work concentration or active growth plans requiring upfront cash before revenue arrives
Multiple owners or limited personal owner liquidity as a backup

Factors that allow for closer to 10%:

Stable, diversified pipeline with predictable start dates and consistent milestone tracking
No single client representing more than 10% of revenue
Small, well-established subcontractors with predictable payment patterns and manageable job costs.
Steady year-round work and strong personal owner liquidity as a backup
Meaningful mix of service or smaller, repeatable jobs that bill and collect quickly, providing consistent cash inflow alongside larger project work
Line of credit secured in advance as a secondary cushion for timing gaps, not a replacement for a properly funded reserve

Keep Your Construction Cash Reserve in a Separate Account

Once you have a reserve target, structure matters. We recommend three separate accounts:

Operating account: Hold roughly two payrolls here as a working balance for day-to-day vendor payments, payroll, and short-term liquidity needs.
Reserve account: Everything above the operating balance goes here — interest-bearing, low risk, and accessible. A high-yield savings or money market account keeps it earning without locking it away.
Tax account: Set aside approximately 40% of forecasted taxable income here on a rolling basis. Construction companies with variable revenue are more exposed to tax surprises; a dedicated account removes that variable.

In construction, account separation matters more than in industries where revenue arrives in regular monthly increments. Milestone payments arrive in lump sums — sometimes several weeks apart. Without a separate reserve account, those lump sums tend to get absorbed into operating needs before they can be allocated intentionally. The protocol should be clear before the payment arrives: cover payables, replenish the reserve, move the remainder. Without that structure, the reserve gets consumed and rebuilt inconsistently.

Secure a Line of Credit Before You Need It

Regardless of where a construction company falls on the 10–30% spectrum, we recommend securing a line of credit equal to the reserve target and securing it well before it’s needed. The cash reserve is the first line of defense when a milestone payment is delayed, or an unexpected cost emerges mid-project.

Lenders extend credit based on financial strength, not need. So build the relationship and secure the credit while the financials look good.

Supporting Your Cash Position Over Time

In construction, the reserve and the forecast are inseparable. If a milestone slips, it delays the billing trigger, which delays the cash, which affects what the reserve can cover. Knowing when that slip is coming, and how far it will push the cash position, requires a cash flow forecast built around milestone timing rather than projected monthly averages.

For construction clients, our Virtual CFOs build two layers of financial modeling that stay in sync: a high-level monthly forecast tied to the project pipeline, and a 13-week cash flow forecast and cash flow statement model that maps when cash is expected to arrive against when payments are due. We reconcile the two so that the ending cash balance in the short-term model aligns with the monthly projection. This is why cash flow management in construction requires weekly oversight rather than periodic review.

A few key habits that help construction companies protect and build their reserves:

Set aside a fixed percentage of each milestone payment toward the reserve before allocating the remainder to operations
Review the reserve position in every weekly cash flow meeting, not just at month-end
Build the gap between your current reserve and your target into the cash flow forecast as a funded objective with a timeline
Secure a line of credit equal to your reserve target before the reserve runs low
Use short-term and long-term forecasting together so strategic decisions stay grounded in real cash timing

To learn more about working with a Virtual CFO advisor, contact us today.