Free cash flow to the firm

The cash a business produces for everyone who funded it, measured before any payment to lenders. It is the input to an enterprise-value discounted cash flow.

Build it from operating profit. Tax the operating profit at the marginal rate to get net operating profit after tax, add back depreciation and amortisation because they took no cash, subtract capital expenditure, and subtract the increase in working capital.

A firm with ₹960 crore of operating profit at a 25% tax rate, ₹380 crore of depreciation, ₹460 crore of capital spending and a ₹210 crore working capital build generates ₹430 crore.

The tax figure is the one people get wrong. Taxing operating profit gives a higher tax charge than the company actually paid, because the real charge is calculated after deducting interest. That is deliberate. The tax saving from debt belongs in the discount rate, not in the cash flow, and counting it in both places values the same benefit twice.