How Much Working Capital Line Does Your Business Actually Need

Most owners size their revolving line of credit off habit — whatever the bank offered last renewal, or whatever number felt safe five years ago. That's the wrong starting point. The right number comes from a calculation: how many days of cash does your business need to fund before customers pay, and how much does that cost per day.

Get the number wrong in either direction and it costs you. It’s not catastrophic, but it adds up over time. Undersized, and payroll or a materials order becomes a monthly scramble. Oversized, and you're paying unused-line fees while signaling to external stakeholders that working capital management runs on instinct, not discipline.

The Cash Conversion Cycle Sets the Number

The funding gap in your business is driven by three inputs:

• Days Sales Outstanding (DSO) — how long it actually takes customers to pay, measured from invoice date, not the payment terms printed on the invoice

• Inventory or WIP days — how long cash sits in inventory, or in work-in-progress on jobs not yet billed

• Days Payable Outstanding (DPO) — how long you take to pay your own vendors

Add the first two, subtract the third, and you have your Cash Conversion Cycle — the number of days your business has cash tied up before it converts back to cash in the bank. Multiply that by average daily operating costs, and you have the actual funding gap the line needs to cover.

A business with fast-paying customers, thin inventory, and vendor terms that stretch 45 days needs a fraction of the line that a business carrying 60 days of receivables and heavy WIP needs — even at identical revenue. Revenue is not the sizing variable. The cash conversion cycle is.

Build in a Buffer, Not a Guess

The base calculation gets you the steady-state number. Two things should move it higher: growth and seasonality. A business growing 20% a year needs incrementally more working capital every year just to fund the same cycle at a larger scale — the line should be sized for where the business is heading, not where it sits today. Seasonal businesses need enough headroom to fund the buildup ahead of peak season, before that season's receivables come in.

Why This Matters Beyond Cash Flow

A line sized off a defensible calculation is also a diligence asset. Most lower-market businesses we see have never run this exercise — the line was set by whatever the bank proposed, and nobody has revisited it since. When a buyer's lender underwrites the business post-close, an owner who can walk through DSO, WIP days, and DPO and explain exactly why the line is sized where it is looks like a business that runs on process. An owner who says "that's just what we've always had" does not.

Revisit It, Don't Renew It on Autopilot

Re-run the calculation annually, and any time customer mix, payment terms, or growth rate shifts materially. A line that was right three years ago is rarely right today. The exercise takes an afternoon of AR and AP aging data — and it changes the conversation with your bank from asking for money to presenting a number you can defend.

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Indure Point's Strategic Advisory practice helps lower-market business owners build the financial infrastructure — including working capital planning — that supports growth. If you want a second opinion on how your line is sized, let's talk