How to calculate Working Capital and why it matters

Working capital: what it is, how it affects liquidity, and where the typical traps hide

There are businesses that show solid profit but constantly feel a cash shortage. There are those growing 40% a year — and they hit a liquidity gap precisely because of that growth. And there are owners who don't understand why, with revenue rising, the bank balance somehow isn't.

In most of these cases the reason is the same: misunderstood or uncontrolled working capital.

Working Capital is one of those concepts every finance person knows and almost no small-business owner does. Which is a shame — because it explains exactly why "we have money" and "we don't have money" can both be true at the same time.

What working capital is: definition without jargon

Working Capital is the difference between a business's current assets and current liabilities.

Working Capital = Current Assets – Current Liabilities

Current assets — things that can be converted into cash within 12 months:

• Cash in bank and on hand
• Accounts receivable (money customers owe you)
• Inventory (goods in the warehouse, raw materials, work in progress)
• Short-term financial investments
• Prepayments to suppliers

Current liabilities — things that need to be paid within 12 months:

• Accounts payable (money you owe suppliers)
• Short-term loans and overdrafts
• Accrued but unpaid wages and taxes
• Advances received from customers (you haven't delivered the service yet)
• The current portion of long-term loans

Example:

Current assets	Amount
Cash in bank	180,000
Accounts receivable	340,000
Inventory	210,000
Prepayments to suppliers	45,000
Total current assets	775,000

Current liabilities	Amount
Accounts payable	280,000
Accrued wages and taxes	95,000
Customer advances	60,000
Total current liabilities	435,000

Working Capital = 775,000 – 435,000 = 340,000

Working Capital is positive — good. But is it enough? And why does it matter at all? The answer lies in what it actually shows.

What working capital tells you about a business

Working Capital is a "liquidity buffer." It shows how much will be left in the business after all current obligations are paid.

Positive Working Capital means current assets exceed current liabilities. The business can pay off all short-term debts and still have resources to operate. Generally a good signal.

Negative Working Capital means current liabilities exceed current assets. If all creditors demanded payment at once — the business couldn't cover it. Not always a disaster (some business models function normally with negative WC), but it needs careful monitoring.

Zero Working Capital — the breakeven point, which in real life means a very thin safety margin.

When negative working capital is normal

There are business models where negative Working Capital is a structural feature, not a problem:

• Retail and supermarkets. Customers pay immediately (or even in advance via gift cards), while suppliers give 30–60 day terms. Payables are always higher than receivables — and that's normal.
• Subscription business (SaaS, memberships). Customers pay up front, but the service is delivered over a month or a year. Advances received are a current liability that temporarily makes WC negative.

But for most B2B companies, manufacturers, and service businesses, negative Working Capital is a problem signal.

Current Ratio and Quick Ratio: reading working capital in proportions

The absolute value of Working Capital depends on the size of the business and says little without context. That's why ratios are used.

Current Ratio

Current Ratio = Current Assets / Current Liabilities

For our example: 775,000 / 435,000 = 1.78

Benchmarks:

• < 1.0: current assets are less than liabilities — potential problem
• 1.0–1.5: acceptable, but the margin is thin
• 1.5–2.5: healthy range for most businesses
• > 3.0: possibly too much money "frozen" in inventory or receivables

Quick Ratio

Current Ratio includes inventory, which can't always be converted to cash quickly. Quick Ratio is the stricter version:

Quick Ratio = (Current Assets – Inventory) / Current Liabilities

For our example: (775,000 – 210,000) / 435,000 = 565,000 / 435,000 = 1.30

Benchmarks for Quick Ratio:

• < 1.0: without inventory you can't cover current liabilities — serious signal
• 1.0–1.5: normal
• > 1.5: good liquidity cushion

In our example Current Ratio = 1.78, Quick Ratio = 1.30. The difference is explained by significant inventory (210,000). If the inventory is liquid — fine. If it's stale stock that's hard to sell — Quick Ratio reflects reality more accurately.

The working capital cycle: where the money actually hides

Now the most important part — how Working Capital connects to the real movement of cash in the business.

Picture a typical trading or manufacturing business:

1. You pay the supplier for goods → cash converts into inventory
2. Goods are sold to the customer → inventory converts into receivables (if there's payment terms)
3. The customer pays → receivables convert into cash

This cycle is called the Cash Conversion Cycle (CCC).

CCC = DSO + DIO – DPO

Where:

• DSO (Days Sales Outstanding) — how many days customers take to pay after invoicing
• DIO (Days Inventory Outstanding) — how many days goods sit in stock before being sold
• DPO (Days Payable Outstanding) — how many days you hold debt to suppliers

Example:

Metric	Value
DSO (customers pay on average in)	45 days
DIO (goods sit in stock on average)	30 days
DPO (you pay suppliers in)	20 days
CCC = 45 + 30 – 20	55 days

This means: from the moment you spent cash on purchasing to the moment cash returns from the customer — 55 days pass. During those 55 days the money is "frozen" in the operating cycle.

The longer the CCC — the more Working Capital you need to finance operations. The shorter — the less.

What happens as the business grows:

Revenue doubled. You need twice the inventory. Receivables also doubled. But the cash on hand didn't grow — on the contrary, it fell, because you had to invest in more inventory and wait for payment from more customers.

That's exactly why a growing business can feel an acute cash shortage while profit is rising. It's not a paradox — it's the math of working capital.

How to improve working capital: three levers

There are three main ways to improve the working capital situation. All three come down to shortening the CCC.

Lever 1. Shorten DSO — speed up collections

How to calculate:

DSO = Accounts Receivable / (Revenue / 365)

If receivables are 340,000 and annual revenue is 2,760,000:

DSO = 340,000 / (2,760,000 / 365) = 340,000 / 7,562 = 45 days

How to shorten:

• Issue invoices immediately — not a day or two after work is finished
• Set up automated reminders: 3 days before the due date and on the day itself
• Offer a discount for early payment (1–2% for payment within 10 days is often cheaper than a credit line)
• For new clients or large projects — require partial prepayment
• Maintain a customer scoring system: who always pays on time and who regularly delays

Shortening DSO from 45 to 30 days for a business with 2.76M annual revenue frees up: (45 – 30) × 7,562 = 113,430 — cash returned to circulation without a single new sale.

Lever 2. Shorten DIO — optimize inventory

How to calculate:

DIO = Inventory / (Cost of Goods Sold / 365)

How to shorten:

• ABC analysis of inventory: category A (80% of revenue) — keep a minimum stock but never allow a stockout; category C (5% of revenue) — consider dropping or ordering only against a specific customer order
• Optimize the reorder point: order less, more often (if the supplier allows)
• Liquidate stale stock even at a discount — frozen money costs more than the discount

Lever 3. Increase DPO — extend payments to suppliers

How to calculate:

DPO = Accounts Payable / (Cost of Goods Sold / 365)

How to increase:

• Negotiate longer terms: if it's 20 days now — ask for 30 or 45. For a reliable customer, a supplier often agrees
• If a supplier offers a prepayment discount — calculate whether it's worth it compared to the cost of cash for you
• Don't pay early without a strong reason — early payment hands the supplier your working capital for free

Important: increasing DPO doesn't mean "delay payments." It means using the full contractual term. If the contract gives you 30 days — pay on day 30, not day 5.

Typical working capital traps

Trap 1. Not factoring WC into growth planning

A company plans to grow revenue 50% in a year. The business plan covers new hires, marketing budget, maybe new equipment. But nobody calculated how much additional Working Capital will be needed to finance bigger inventory and bigger receivables.

Estimation formula:

Additional WC = Revenue increase × (DSO + DIO – DPO) / 365

If revenue increase = 1,380,000 and CCC = 55 days:

Additional WC = 1,380,000 × 55 / 365 = 207,945

Almost 208,000 of additional financing will be needed just to support working capital during growth. If this isn't built into the plan — the cash gap will hit precisely at the moment of growth.

Trap 2. Treating all receivables as "good"

Accounts receivable on the balance sheet — 340,000. Looks like an asset. But if you dig in:

• 180,000 — current, within contractual terms
• 100,000 — overdue 30–60 days
• 60,000 — overdue more than 90 days, the customer has "vanished"

Real liquid receivables are 180,000, not 340,000. Working Capital and liquidity ratios need to be calculated adjusted for the quality of receivables.

What to do: every month, build an aging report of receivables by overdue bucket. Receivables > 90 days without a confirmed payment plan — move to a reserve.

Trap 3. Not separating operating and financial WC

There's Working Capital that arises from operating activity (inventory, receivables, payables) — operating WC. And there's "financial" WC — short-term loans, overdrafts, deposits.

The problem is when operating WC is negative and total WC turns positive only thanks to short-term loans. Formally, all good. In reality — the operating cycle is being financed with borrowed money, which raises both risk and the cost of capital.

Trap 4. Ignoring seasonality

In a seasonal business, Working Capital naturally swings through the year. Before the peak season — inventory accumulates, WC grows, financing is needed. After the peak — inventory sells through, receivables convert, WC drops.

If you plan WC only from the "average" — you can hit a gap right before the season, exactly when you need stock most.

What to track monthly: the minimum monitoring

You don't need to calculate all these metrics every week. But once a month — it's worth seeing this picture:

Metric	Current month	Previous month	Trend
Working Capital (abs.)	340,000	310,000	↑
Current Ratio	1.78	1.65	↑
Quick Ratio	1.30	1.28	→
DSO (days)	45	48	↑ improving
DIO (days)	30	35	↑ improving
DPO (days)	20	20	→
CCC (days)	55	63	↑ improving

Trends matter more than absolute values. If WC is steadily rising — the business is building a liquidity cushion. If it's falling while revenue is rising — there's a problem in the operating cycle.

Summary

Working Capital isn't an accounting concept. It's the answer to "where is the money actually, and why don't I see it on the account?"

Three key thoughts worth remembering:

First: positive Working Capital doesn't guarantee no cash gaps — what matters is how liquid it is and what the CCC looks like.

Second: business growth requires additional Working Capital. Plan for it in advance — don't react to the gap.

Third: three improvement levers — shortening DSO, shortening DIO, increasing DPO — are concrete operating decisions, not financial tricks. They improve both business processes and liquidity at the same time.

Next in the series — "Rolling Forecast vs annual budget: what fits a small business."