Wobbe Index

Wobbe Index WI = HHV / √SG - measure of thermal energy delivered through a fixed orifice. Combustors are rated by Wobbe, not calorific value.

LNGGas composition

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

WI = \frac{HHV}{\sqrt{SG}}

Symbol	Meaning	Unit
$HHV$	Gross calorific value	MJ/m³
$SG$	Specific gravity vs dry air

Source: ISO 6976 - Natural gas calorific value; EN 437 - Wobbe family bands

Wobbe Index WI = HHV / \u221aSG - measure of thermal energy delivered through a fixed orifice.