Working Capital Calculator
Find UK business working capital and current ratio.
What this calculator does
This working capital calculator measures the buffer between what a business owns short term and what it owes short term. Enter current assets and current liabilities, and it returns working capital in pounds alongside the current ratio — the same relationship expressed as a multiple rather than an amount.
The two figures answer different questions. Working capital gives the absolute cushion available to absorb a slow month or fund a large order. The current ratio gives the proportion, which is what makes it comparable across businesses of different sizes and what lenders write into facility agreements as covenants.
When to use it
The most important use is before accepting growth. A large new contract or a step change in volume consumes working capital before it produces profit, and UK businesses fail this way far more often than they fail for lack of demand. Work out the funding gap before signing rather than after.
It is also the right tool for a seasonal stock build, where purchases and the debtors that follow can absorb the entire cushion at precisely the point in the year when flexibility is lowest. And it is what to check ahead of a covenant test date, since stock and debtor growth both move the ratio in ways easy to miss month to month.
Understanding the inputs
Current assets are everything convertible to cash within twelve months: cash at bank, trade debtors net of bad debt provision, stock, prepayments, and any VAT recoverable. Be realistic about debtor and stock quality — an aged debtor and obsolete stock both sit at full value on the balance sheet and at considerably less in practice.
Current liabilities are everything due within twelve months: trade creditors, accruals, wages and PAYE, VAT due to HMRC, corporation tax payable within the year, the current portion of any loan, and a drawn overdraft. The VAT and corporation tax lines are the ones most often understated, and both can be substantial.
How is this calculated?
Working Capital = Current Assets − Current Liabilities. Current Ratio = Current Assets / Current Liabilities.
A worked example
A business holds £585,000 of current assets against £320,000 of current liabilities, giving working capital of £265,000 and a current ratio of 1.83 — reasonable by conventional standards.
Now look at how that capital is trapped. With 73 days of stock, 45 debtor days, and 40 creditor days, the cash conversion cycle is 78 days. On £2.1 million of annual turnover, that is roughly £449,000 locked in the operating cycle. Taking 15 days out through faster collection and tighter stock would release about £86,000 permanently. Growing turnover 30 percent, meanwhile, would demand around £80,000 more working capital than the business currently holds.
Limitations and assumptions
The calculation is a snapshot and assumes every current asset genuinely converts. Aged debtors and obsolete stock both sit at full book value while being worth far less, so two businesses reporting identical working capital can be in entirely different positions.
It also says nothing about timing within the year, so a healthy figure can coexist with a wage run you cannot meet next week or a VAT payment falling due at the wrong moment. It ignores undrawn overdraft headroom and can be flattered by deferring supplier payments across the balance sheet date. Read it with an aged debtor report, an aged stock report, and a rolling thirteen-week cash forecast.
Common Questions
- What is adequate working capital?
- A current ratio between 1.5 and 2.0 is generally healthy for most businesses. Below 1.0 means short-term liabilities exceed short-term assets, which is a warning sign. Above 3.0 often indicates capital sitting idle in debtors or stock rather than working, so a higher figure is not automatically better.
- Why do growing businesses run out of cash?
- Because growth consumes working capital before it generates profit. Every new order means buying stock and paying wages weeks before the customer settles. Growing 30 percent typically requires around 30 percent more working capital, which must be funded from somewhere — and retained profit rarely arrives quickly enough.
- What is the cash conversion cycle?
- Days of stock plus debtor days minus creditor days. It measures how long cash is tied up between paying a supplier and being paid by a customer. A 78-day cycle on £2.1 million of turnover means roughly £450,000 permanently locked inside the business rather than sitting in the bank.
- How does VAT affect working capital?
- Significantly, and in both directions. VAT collected sits in your account until the quarterly return falls due, which temporarily flatters cash. VAT on purchases is recoverable but only after the return. Businesses that mistake the VAT balance for available working capital get caught out reliably every quarter.
- Can working capital be negative and the business still be sound?
- Yes, and some of the strongest models work that way deliberately. Supermarkets and pubs collect from customers instantly while paying suppliers on 30 or 60 day terms, so customers effectively fund operations. Negative working capital is only dangerous when it arises from distress rather than from the business model.
- How do I release working capital without borrowing?
- Attack the cycle from three directions: invoice on delivery and chase overdue accounts systematically, reduce slow-moving stock even at a discount, and negotiate longer supplier terms. Ten days off the cash conversion cycle typically frees around a third of a month's turnover permanently, with no interest cost.
- What about invoice finance?
- Invoice discounting and factoring convert debtors into cash immediately, which shortens the cycle at a cost. Charges are usually expressed as a discount fee plus a service fee, and the effective annual rate can be high. It suits businesses growing faster than retained profit can fund, but it is expensive as a permanent arrangement.
- How much working capital does a large new contract need?
- Calculate the gap directly: materials plus labour spent before payment arrives, multiplied by the time to collection. A contract requiring £150,000 of outlay over 90 days before any payment needs £150,000 of funding. Winning work without arranging that is how profitable businesses end up in difficulty.
- Do lenders impose working capital covenants?
- Frequently, either as a minimum current ratio or a minimum absolute figure, tested quarterly with a director's certificate. Breaching it is an event of default even when every payment is current. Since stock builds and debtor growth both move the ratio, seasonal businesses should check headroom before their peak.