Segment margin

Segment result divided by segment revenue. It shows which part of a group actually earns, and it is disclosed in enough detail to build a five-year table.

A chemicals segment turning ₹2,200 crore of revenue into ₹410 crore of result runs at 18.6%.

Compare it with the standalone peers in the same business. That comparison pays. If the group's chemicals segment earns 18.6% while three listed chemicals companies earn 24%, either the group's mix is different or its chemicals business is worse than the sector, and the answer changes the valuation.

Allocation choices affect the number. Corporate costs pushed into one segment and away from another move both margins without changing anything real, so read the basis of allocation in the note before treating a gap as performance.