Working Capital Explained — Formula, Examples & How to Manage It
Working capital is the money a business has available for its day-to-day running costs — paying suppliers, staff, and overheads before customer payments come in. Running out of it, not lack of profit, is the single most common reason a growing small business fails.
What Is Working Capital?
Working capital is the cash a business has tied up in (or available for) its short-term, day-to-day operations. It measures whether you can cover your near-term bills without needing to sell a long-term asset or arrange emergency finance.
How to Calculate Working Capital
Working capital = current assets (cash, money owed to you by customers, and stock you expect to sell or use within 12 months) minus current liabilities (money you owe suppliers, short-term loans, and other bills due within 12 months).
Worked example: A small retailer has £15,000 in the bank, £8,000 owed by customers (debtors), and £12,000 of stock — current assets of £35,000. It owes suppliers £10,000 and has a £5,000 short-term loan repayment due — current liabilities of £15,000.
Working capital = £35,000 − £15,000 = £20,000
A positive figure means the business can, in principle, cover its short-term obligations. A negative figure — where current liabilities exceed current assets — is a warning sign that needs addressing before it becomes a cash crisis, even if the business is profitable on paper.
Why Working Capital Matters More Than Profit, Short-Term
A business can be profitable and still run out of cash. This happens most often when:
- Customers pay slowly. If you invoice on 30-day terms but customers routinely pay in 60 or 90, you are effectively financing your customers' businesses with your own cash.
- Stock ties up cash. Money spent on inventory sitting in a warehouse isn't available to pay this month's bills.
- Growth outpaces cash flow. Winning a big new order is good news, but if you have to pay suppliers and staff to fulfil it weeks or months before the customer pays you, rapid growth can be what actually causes a cash crunch — sometimes called "overtrading".
Financing a Working Capital Gap
The general rule is that short-term needs should be met with short-term finance — not by taking out a long-term loan or remortgaging an asset to cover a temporary cash gap. Common options, roughly in order of typical cost:
- Business bank account overdraft — the simplest option for short, unpredictable gaps; see our business bank account comparison for providers that offer one.
- Invoice finance — release cash tied up in unpaid customer invoices (typically up to 90% of the invoice value, within a day or two) rather than waiting the full payment term. Covered in more detail on our business loans page.
- Short-term business loan — a fixed-term loan for a defined gap, repaid as cash flow recovers.
- Trade credit from suppliers — negotiating longer payment terms with your own suppliers is a free way to ease pressure, and is often overlooked.
- Start Up Loans — if the gap is part of your initial launch costs rather than an ongoing cycle, a Start Up Loan (£500–£25,000, government-backed) may be more appropriate than short-term borrowing.
Additional working capital funding almost always carries a cost premium — higher overdraft charges, arrangement fees, or a requirement for security — so the better long-term fix is usually to manage the cycle itself (see below) rather than to keep borrowing to cover it.
Monitoring and Managing Working Capital
Every business should track its working capital position regularly, not just at year-end. Practical steps:
- Keep accurate, up-to-date accounting records so you always know your real cash position, not just what's in the bank today.
- Build a rolling cash flow forecast — this is the single best early-warning tool for a working capital gap, because it shows a shortfall weeks before it actually happens.
- Invoice promptly and chase late payers — every extra week a customer takes to pay is a week that cash isn't available to you.
- Review stock levels — holding less inventory (or negotiating sale-or-return terms) frees up cash that would otherwise sit on a shelf.
- Negotiate supplier payment terms in advance of needing them, not during a crisis, when you have far less leverage.
A strong balance sheet with valuable fixed assets is irrelevant if a business can't pay its immediate bills — this is exactly the scenario where creditors can petition to wind up an otherwise viable company. Working capital, not net worth, is what keeps the lights on week to week.