Quick answer
The working capital cycle is the time between paying for inputs such as stock, materials and wages and receiving cash from customers. It is roughly stock days plus debtor days minus creditor days. The longer the cycle, the more cash the business must fund itself or borrow. Growth lengthens the funding need because more sales mean more cash tied up in the cycle at once.
Key points
- Cycle ≈ stock days + debtor days − creditor days.
- Every day cut from the cycle frees cash.
- Growth increases the cash tied up in the cycle.
- Finance can fund the cycle, but shortening it is cheaper.
Checklist
- Stock days measured
- Debtor days measured
- Creditor days measured
- Cycle length calculated
- Actions to shorten each part
Profit and cash are not the same thing, and the working capital cycle is the reason. It measures how long money is tied up between the moment you pay for something and the moment a customer pays you for the result. Understanding your cycle explains why a busy, profitable business can feel permanently short of cash, and it shows exactly where to look for relief.
The three parts of the cycle
| Part | Question it answers |
|---|---|
| Stock days | Average time goods and materials wait on the shelf before sale |
| Debtor days | Average time between invoicing and customer payment |
| Creditor days | Average time you take to settle supplier bills |
The cycle is roughly stock days + debtor days − creditor days. Take 40 days on the shelf, 45 days to collect and 30 days of supplier credit: the cycle is about 55 days. For 55 days, on average, the business is funding its own operations.
Service businesses with no stock still have a cycle: the time between paying staff for work and being paid by clients.
Why the cycle matters
The longer the cycle, the more cash you need to keep operating. That cash has to come from somewhere: the owner’s funds, retained profits or finance. A business with a 10-day cycle needs far less working capital than one with a 90-day cycle, even at the same sales.
Why growth makes it harder
When sales rise, the cycle does not get shorter; it just involves more money. Double the sales and you roughly double the stock and unpaid invoices tied up at any time. That is why fast-growing businesses so often run short of cash, and why lenders ask about growth plans. Our working capital loans review explains how finance can carry growth.
How to measure your cycle
Use your last financial year:
- Debtor days = trade debtors ÷ annual credit sales × 365.
- Stock days = average stock ÷ annual cost of goods sold × 365.
- Creditor days = trade creditors ÷ annual credit purchases × 365.
Your accountant can calculate these quickly, and many accounting systems report them. Track them quarterly to see the trend.
Shortening each part
Debtor days: invoice immediately, shorten terms for new customers, ask for deposits, make paying easy and follow up promptly. Our guide to slow-paying customers covers practical steps.
Stock days: reduce slow-moving lines, improve forecasting, order smaller quantities more often where economical, and negotiate consignment or shorter lead times.
Creditor days: negotiate longer terms with suppliers, particularly where you buy regularly. Avoid paying late without agreement, which damages relationships.
Financing the cycle
Some cycle is unavoidable. Finance designed for it includes:
- a line of credit or overdraft for recurring needs;
- invoice finance, which funds debtor days directly;
- trade finance, which funds supplier payments and stock in transit.
Using long-term loans for working capital, or short-term facilities for long-term assets, tends to cause problems. Match the finance to the job.
An illustrative example
A made-up wholesaler calculates a cycle of about 70 days. It moves larger customers from 45 to 30-day terms, clears several slow-moving lines and negotiates 45-day terms with its main supplier. The cycle falls to about 40 days. On the same sales, the business now needs much less working capital, and its line of credit limit can be reduced, saving fees.
Negative cycles
Some businesses collect cash before paying suppliers: cafés paid by card and supplied on 30-day terms, or subscription businesses billing in advance. Their cycle is negative, and growth generates cash. If your business can shift towards upfront payment or deposits, you move in that direction.
Watching the cycle over time
A cycle that is lengthening is an early warning sign, often appearing before a cash shortage is obvious. Tracking the three measures each quarter lets you act early.
Seasonality and the cycle
Many businesses do not have one cycle but several across a year. A retailer’s stock days balloon before Christmas; a builder’s debtor days stretch when a large project is in its later stages; an agricultural supplier’s cycle follows the planting and harvest calendar. Measuring the cycle only at year end can hide these swings. If your business is seasonal, look at the measures at the peak and the trough as well, and size any facility to the peak, not the average.
What lenders read into your cycle
Lenders who fund working capital pay close attention to these measures. Rising debtor days can suggest collection problems or customers in difficulty; rising stock days can point to slow-moving or obsolete stock; falling creditor days might mean suppliers are tightening terms. Explaining movements before a lender asks, and showing what you are doing about them, builds confidence and can improve the terms you are offered.
A simple quarterly routine
Each quarter, calculate the three measures, compare them with the last four quarters and pick one action to improve the weakest. Over a year, that steady attention usually frees more cash than any one-off push.
Need to fund your working capital cycle?
If your cycle is tying up more cash than the business can spare, make one enquiry. There is no credit check when you first enquire, a real person reviews it and your details go to one lending partner rather than many. Share your typical customer and supplier terms in your enquiry so the right facility can be suggested.
Frequently asked questions
How do I calculate debtor days?
Divide trade debtors by annual credit sales and multiply by 365. It shows the average number of days customers take to pay.
How do I calculate stock days?
Divide average stock value by annual cost of goods sold and multiply by 365. It shows how long stock sits before it is sold.
How do I calculate creditor days?
Divide trade creditors by annual purchases on credit and multiply by 365. It shows how long you take to pay suppliers.
Can the working capital cycle be negative?
Yes. Businesses that collect cash before paying suppliers, such as some retailers and subscription businesses, can have a negative cycle and generate cash as they grow.
Why does growth create cash problems?
More sales mean more stock and more unpaid invoices at once. Even profitable growth needs extra cash to fund the larger cycle.
Which finance funds the working capital cycle?
Lines of credit, overdrafts, invoice finance and trade finance are designed for it. Long-term loans are better for long-term assets.
Is a long working capital cycle always bad?
Not always. Some industries naturally have long cycles, such as manufacturing or wholesale. What matters is that the business has funding to carry the cycle and that it is not lengthening unexpectedly.
Sources and further reading
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