Stoichiometric air fuel ratio/excess air/equivalence ratio calculator


Calcualte stoichiometric air fuel ratio

Stoichiometric air is minimum theoretical air required for complete combustion of fuel. It depends on elemental composition of fuel. Most common elements present in fuel are carbon and hydrogen.

This calculator considers four most common elements of fuel (i.e carbon, hydrogen, sulphar, oxygen) for calculation of stoichiometric air.

For using this calculator insert mass fractions of fuel elements as percentage in fields of carbon, hydrogen, sulphar and oxygen. Please, remember that this calculator considers amount of fuel as 1 kg. If there is uncombustable matter in fuel like moisture, include it in total mass of fuel for calculating mass fractions of fuel elements. Please note that summation of fuel elements must be 100. Mixing of air and fuel is also an important factor for achiving complete combustion. In practice, fuel is always supplied with some excess air for achiving complete combustion.


Calcualte excess air from CO2 and O2 percentage in flue gas


Calcualte equivalence ratio from known amount of actual and stoichiometric air