working capital（WC）通常翻译为“营运资金”，也称营运资本，亦作net working capital（NWC）。

营运资金为可用来偿还支付义务的流动资产减去支付义务的流动负债的差额，可以用来衡量公司或企业的短期偿债能力，其金额越大，代表该公司或企业对于支付义务的准备越充足，短期偿债能力越好。当营运资金出现负数，也就是一家企业的流动资产小于流动负债时，这家企业的营运可能随时因周转不灵而中断。

营运资金的计算方式：（净）营运资金=流动资产（Current Asset）-流动负债（Current Liability）

流动资产（Current Asset）主要内容有：

存货

应收账款

货币资金（包含现金及银行存款）

交易性金融资产

一年内到期的非流动资产

流动负债（Current Liability）主要内容有：

应付账款

银行透支

交易性金融负债

e.g. Consider the case of XYZ Corp. When XYZ first started, it had NWC of only $10,000, with current assets averaging $50,000 and current liabilities averaging $40,000. To improve its NWC, XYZ decides to keep more cash in reserve and deliberately delay its payments to suppliers to reduce current liabilities. After making these changes, XYZ has current assets averaging $70,000 and current liabilities averaging $30,000. Therefore, its NWC is now $40,000.

可以通过下图了解营运资金的运作方式：