GRM (Gross Refining Margin)
Gross Refining Margin is the difference between the market value of all petroleum products produced by a refinery and the cost of the crude oil feedstock, expressed on a per-barrel basis, and it is the primary profitability metric for Indian oil refining companies.
Refineries are complex industrial facilities that convert crude oil — a raw material — into a range of finished petroleum products including petrol, diesel, jet fuel, LPG, naphtha, fuel oil, and petrochemical feedstocks. The economics of refining depend on two things: the price at which crude oil is purchased, and the prices at which the portfolio of products can be sold. GRM captures this spread in a single per-barrel figure.
The benchmark GRM for Indian refiners is most commonly expressed as a spread over Singapore Complex margins or Dubai crude benchmarks, though companies may also compute their own realised GRM based on the specific crude slate processed and the product slate produced. GRM is calculated by multiplying the yield of each product (how many barrels of each product are produced from one barrel of crude input) by the market price of that product, summing the total product revenue, subtracting the crude cost, and dividing by the number of barrels processed.
Reliance Industries' Jamnagar refinery complex — the world's largest single-location refining complex — has historically commanded premium GRMs compared with benchmark Singapore margins because of its exceptional complexity (Nelson Complexity Index above 21), ability to process a wide variety of cheaper sour or heavy crude grades, and sophisticated petrochemical integration that allowed higher-value products to be produced. During 2022-23, when global refining margins spiked due to the Russia-Ukraine conflict disrupting European refinery supply and strong post-COVID demand recovery, Reliance reported GRMs well above USD 25 per barrel, contributing significantly to its earnings.
Public sector refiners such as Indian Oil Corporation, Bharat Petroleum, and Hindustan Petroleum also disclose GRMs, but their margins have historically been lower than Reliance's due to less complex refinery configurations and a constrained ability to source the widest range of crude grades. MRPL (Mangalore Refinery and Petrochemicals) and Chennai Petroleum (CPCL) are other Indian refiners where GRM analysis is central to earnings modelling.
GRM is volatile because it is driven by global crude oil prices, product crack spreads (the premium of finished products over crude), seasonal demand patterns, and refinery availability across the world. Analysts building earnings models for Indian refiners must make explicit assumptions about GRM rather than relying on stable trend-based estimates, and they use sensitivity analysis to understand how much a USD 1 per barrel change in GRM affects EBITDA.