Non-coking coal in India used to be graded by Useful Heat Value (UHV) into lettered grades. UHV was a calculated figure worked out from ash and moisture, rather than a direct measurement of the heat in the coal.
The Government of India moved non-coking coal to grading by Gross Calorific Value (GCV) — a direct laboratory measurement — in bands of 300 kcal/kg, from G1 (above 7,000 kcal/kg) to G17 (2,201–2,500 kcal/kg). The Ministry of Coal publishes the current grade table.
Older contracts, reports and conversations sometimes still use the UHV letters, so it helps to know both — but current PSU sale and auction terms use the GCV grades.
What it means if you trade coal
Price and quality conversations today run on GCV. If a counterparty quotes an old lettered UHV grade, ask for the GCV and the basis it's reported on before comparing anything.
Sources
- OfficialMinistry of Coal — Coal grades
Coal Boss explanation, based on the sources above. Last checked: 22 September 2026.
