What Is Working Capital?
Working capital measures the short term liquidity that funds day to day operations. In its simplest form it is current assets minus current liabilities. Analysts care less about the level and more about the change, because an increase in net working capital ties up cash and a decrease releases it. Modeling that change correctly is what connects the income statement to real cash flow.
Definition and variants
The headline formula is Working Capital = Current Assets - Current Liabilities. A positive number means short term assets cover short term obligations.
Analysts usually work with net working capital, which excludes cash and debt to focus on the operating items: Net Working Capital = (Receivables + Inventory) - Payables. This isolates the capital genuinely tied up in running the business, separate from financing.
Cash and short term debt are excluded from operating working capital because they belong to the financing and investing story, not the operating cycle.
Worked example in Excel
Place receivables in B2, inventory in B3, and payables in B4. Operating net working capital is the operating assets minus the operating liability.
- Enter
=B2+B3-B4inB5to compute net working capital. - Repeat the calculation for the prior period in column
C. - Compute the change with
=B5-C5. A positive change is a use of cash; a negative change is a source.
| Item | Cell | Value |
|---|---|---|
| Receivables | B2 | 80 |
| Inventory | B3 | 50 |
| Payables | B4 | 40 |
| Net working capital | B5 | 90 |
=B2+B3-B4 returns 80 + 50 - 40 = 90.
The cash conversion cycle
Working capital is the snapshot; the cash conversion cycle is the timing behind it. It measures how many days cash is locked in operations: CCC = DSO + DIO - DPO.
Days sales outstanding is how long customers take to pay, days inventory outstanding is how long stock sits, and days payable outstanding is how long you take to pay suppliers. A shorter cycle frees cash.
- Lower DSO means faster collection of receivables.
- Lower DIO means inventory sells through quickly.
- Higher DPO means you finance operations with supplier credit.
Why the change in NWC matters
On the cash flow statement, the change in net working capital is an adjustment to convert accrual profit into cash. Growth often consumes cash because rising sales require more receivables and inventory before the cash arrives.
A common mistake is sign error. An increase in an asset like inventory reduces cash, while an increase in a liability like payables increases cash. Getting one sign backward can flip a healthy model into a cash drain, so trace the change line carefully against the balance sheet.
Formula Trace
Formula Trace follows the change in net working capital from the balance sheet line items into the cash flow statement so you can verify the sign and the links.
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What is the difference between working capital and net working capital?
Working capital is all current assets minus all current liabilities. Net working capital, as analysts usually mean it, excludes cash and debt to isolate operating items like receivables, inventory, and payables.
Is high working capital good?
Not always. Some buffer protects liquidity, but excessive working capital means cash is tied up in receivables and inventory rather than generating returns. The right level depends on the industry and cycle.
Why does an increase in working capital reduce cash flow?
Because investing more in receivables or inventory consumes cash before it is recovered. On the cash flow statement, a rise in net working capital is subtracted from operating cash flow.