Compute heat released and CO2 produced when a fuel burns completely.
Heat released
How to use this tool
Standard enthalpies for six common fuels are built in.
Use grams or kilograms.
Shown in kilojoules and megajoules.
Carbon dioxide mass assumes complete combustion.
Formula & worked example
Burning 16 g of methane (about 1 mole) releases 890 kJ and produces about 44 g of carbon dioxide.
Limitations — read this before you rely on it
Standard-state values for complete combustion only; real appliances have efficiency losses and incomplete combustion.
Frequently asked questions
The heat released when one mole of a fuel burns completely in oxygen, a negative enthalpy change.
The tool shows heat released as a positive amount of energy; the enthalpy change itself is negative.
Burning with enough oxygen to turn all carbon into CO2 and all hydrogen into water; poor air supply gives soot and carbon monoxide instead.
Hydrogen contains no carbon, so its only combustion product is water.
Standard enthalpies at 25 C; real fuels and conditions vary slightly.