The amount of money it has available to spend on its day-to-day business operations, such as paying short term bills and buying inventory. We use the definition of Joel Greenblatt and exclude excess cash as this is not needed to conduct the business. We also exclude short term interest bearing debt from the current liabilities, as Greenblatt only looks at payables for which the company does not need to pay interest.

$$\mathrm{Net\; Working\; Capital}=\mathrm{MAX(}\mathrm{Current\; Assets}-\mathrm{Excess\; Cash}-(\mathrm{Current\; Liabilities}-(\mathrm{Total\; Debt}-\mathrm{Long\; Term\; Debt}\left)\right)\mathrm{,\; 0})$$