What calorific value does India use for natural gas per SCM?

PPAC's gas conversions, sourced from GAIL, use a gross calorific value of 10,000 kcal per SCM, with net calorific value at 90% of that. One MMBtu equals 25.2 SCM on this basis. Domestic production averages 8,000 to 9,480 kcal per SCM, so use the GCV on your own bill when it is printed.

The reference values

• 1 SCM = 1 cubic metre at 1 atmosphere and 15.56 C.
• Gross calorific value: 10,000 kcal per SCM. Net calorific value: 90% of GCV.
• 1 MMBtu = 25.2 SCM at 10,000 kcal per SCM; 1 MMBtu = 252,000 kcal.
• Density of gas: 0.76 kg per SCM; specific gravity 0.62.
• Average natural gas production in India: 8,000 to 9,480 kcal per SCM (Table 9.1).

From SCM to CO2

1. Multiply SCM by the GCV on your bill, or 10,000 kcal if none is printed.
2. Take 90% for net calorific value and convert to GJ (1 kcal = 4.19 kJ per PPAC).
3. Multiply by the IPCC natural gas default of 56.1 kg CO2 per GJ.

Why your figure may differ

On these PPAC values one SCM works out to about 2.12 kg CO2, while 0.76 kg per SCM times the IPCC per-kg factor gives about 2.05. The two reference values imply slightly different gas. A bill that prints GCV settles it for your supply.

Worked example

• 1,000 SCM x 10,000 kcal = 10,000,000 kcal GCV.
• NCV = 9,000,000 kcal x 4.19 kJ = 37.71 GJ.
• CO2 = 37.71 x 56.1 = 2,116 kg.

Uses PPAC reference values, not a specific bill.

What Senseible does here

Senseible reads the quantity and unit printed on each fuel invoice, converts it with a stated density or calorific value, and shows the factor and source on every line, so a litre or kilogram is never guessed.

• PNG bill in MMBtu to CO2
• GCV vs NCV in fuel calculations
• SCM vs Nm3

Sources: PPAC Ready Reckoner FY 2025-26, Chapter 9 conversion tables, IPCC 2006 Guidelines, Volume 2 (Energy), default factors

Last reviewed 2026-10-23.