Tomás Delgado signed the best quarter in the eleven-year history of Tidewater Marine Supply. His Savannah distribution business moved $1.4 million in propellers, deck hardware, and outboard parts to boatyards across coastal Georgia. Gross margin held at 31%. His accountant confirmed the profit.
Two weeks later he could not make a $58,000 payroll run without drawing on his line of credit.
Nothing was wrong with his pricing, his sales team, or his books. His problem was timing. He had paid his suppliers on day 30 and would not see cash from those same parts until day 101. Why? It’s called the cash conversion cycle.
The three numbers that own your bank balance
The cash conversion cycle counts the days between the moment cash leaves your business and the moment it returns. Three activity ratios build it.
CCC = DIO + DSO − DPO
Days inventory outstanding measures how long stock sits before it sells.
DIO = (Average Inventory / COGS) × 365
Days sales outstanding measures how long it takes customers to pay after you invoice them. Use credit sales here, not total revenue, because cash and card sales never create a receivable.
DSO = (Average Accounts Receivable / Credit Sales) × 365
Days payable outstanding measures how long it takes you to pay vendors. This is the only component where a higher number helps you.
DPO = (Average Accounts Payable / COGS) × 365
Running Tomás's numbers
| Line item |
Amount |
| COGS (trailing 12 months) |
$3,864,000 |
| Credit sales |
$5,600,000 |
| Average inventory |
$624,000 |
| Average accounts receivable |
$736,000 |
| Average accounts payable |
$328,000 |
DIO = ($624,000 / $3,864,000) × 365 = 59 days
DSO = ($736,000 / $5,600,000) × 365 = 48 days
DPO = ($328,000 / $3,864,000) × 365 = 31 days
CCC = 59 + 48 − 31 = 76 days
Seventy-six days. Every dollar Tomás spends on inventory is tied up for two and a half months before it comes back. His suppliers finance 31 of those days. He finances the other 45 out of his own pocket.
This metric is worth separating from the one it is often confused with. The operating cycle is DIO plus DSO, which in Tomás's case is 107 days. That counts the full trip from receiving a propeller to collecting the cash for it. Subtracting DPO is what turns an operational stopwatch into a cash measurement, because trade credit means your own money was never tied up for the whole 107 days.
Three measurement mistakes distort this number badly enough to make it useless. Running DSO on total revenue rather than credit sales understates it, since cash and card transactions never sat in receivables. Pulling a single balance sheet date rather than averaging across months lets one large payment flatter the result for a period. Reviewing the cycle quarterly instead of monthly hides the drift until a payroll run exposes it.
Why growth makes this worse
Here is the part that catches owners off guard. A longer cycle does not just slow cash down. It scales with revenue.
If Tomás doubles sales next year and the cycle stays at 76 days, the working capital locked inside operations roughly doubles too. More inventory on the shelf, more receivables in the aging report, and the additional cash has to come from somewhere. The income statement will look excellent. The bank account will look worse than it does today.
Businesses fail during growth for exactly this reason. Demand was never the constraint. The cash conversion cycle ran longer than the cash runway.
What good looks like
There is no universal target, because the cycle is a function of the business model.
| Business type |
Typical
CCC |
Why |
| Grocery and fast-moving retail |
Under 10 days |
Cash at the register, vendors paid weeks later |
| Distributors and wholesalers |
30 to 90 days |
Inventory plus trade credit terms |
| Aerospace and heavy manufacturing |
100+ days |
Long production lead times, slow collections |
| Ecommerce, subscription, ticketing |
Negative |
Customers pay before suppliers do |
A negative cycle means customers fund your operations. Growth generates working capital instead of consuming it. Online retailers and subscription businesses live here, which is one reason a single CCC number should never be compared across industries.
The trend beats the benchmark. A distributor moving from 76 days to 84 days has a problem worth investigating even if 84 is normal for the sector.
Seasonality complicates the read. Tidewater builds inventory in February for the spring boating season, so a February 28 balance sheet shows a far longer cycle than a September 30 one. That swing reflects the calendar, not performance. Businesses with concentrated seasons should compare the same period year over year and track peak and off-peak cycles separately, because working capital needs differ sharply between them.
Three levers, one of them fastest
Cutting DSO is usually the quickest win for a small business. Invoice the day the shipment leaves. Shorten terms from net 45 to net 30. Offer a 2% discount for payment within 10 days. Set up ACH debit authorization so payment pulls on the due date instead of waiting for a customer to remember.
Cutting DIO takes longer. Better demand forecasting, fewer slow SKUs, and smaller, more frequent purchase orders all reduce average inventory without hurting fill rates.
Extending DPO means using the full terms you already have. Paying a net 30 invoice on day 30 rather than day 12 is free cash. Paying on day 45 is not a strategy; it is a late payment that eventually costs you terms, discounts, and vendor goodwill.
Tomás did two things. He moved his three largest boatyard accounts onto ACH debit and cut DSO to 34 days. He also stopped paying vendor invoices the week they arrived and started paying them on the due date, which lifted DPO to 44 days.
Twenty-seven days shaved off the cycle. On $3.86 million of COGS, that freed up roughly $286,000 of cash that had been sitting in his own operations. No loan, no new customers, no price increase.
The number to pull this month
Calculate your cycle using trailing twelve-month averages, not a single balance sheet date. A large customer payment landing on December 31 will flatter your DSO and mislead you in January.
Then track it monthly against itself. Rising means cash is getting trapped. Falling means the business is funding its growth. Tomás still books the same revenue he did in his best quarter. The difference is that the money now shows up while he still needs it.
