How can we calculate the need in prognostic working capital? What depends need working capital?

By definition, working capital is the amount by which current assets exceed current liabilities. However, if you simply run this calculation each period to try to analyze working capital, you won't accomplish much in figuring out what your working capital needs are and how to meet them.A more useful tool for determining your working capital needs is the operating cycle. The operating cycle analyzes the accounts receivable, inventory and accounts payable cycles in terms of days. In other words, accounts receivable are analyzed by the average number of days it takes to collect an account. Inventory is analyzed by the average number of days it takes to turn over the sale of a product (from the point it comes in your door to the point it is converted to cash or an account receivable). Accounts payable are analyzed by the average number of days it takes to pay a supplier invoice.