Net profit margin

Net profit divided by revenue. What survives from each rupee of sales after every cost.

The exporter earning ₹615 crore on ₹4,800 crore of revenue runs a 12.8% net margin.

Because it sits below interest and tax, the measure mixes trading performance with financing and tax choices. A margin that improved because the company refinanced debt at a lower rate is a real improvement for shareholders and tells you nothing about the products.

Compare it with the operating margin trend to see which is which.