Stoichiometric Combustion Calculator

Related Calculators

Fuel Blend Calculator Dry Basis to Wet Basis Calculator Combustion Residence Time Calculator Combustion Chamber Pressure Calculator

Stoichiometric Combustion Calculator: Molar Air and Oxygen Requirement

Combustion stoichiometry on a molar basis is the foundation for balancing chemical equations, sizing burners, and predicting flue gas composition. This calculator computes exactly how many moles of oxygen and air are needed to completely combust one mole of a hydrocarbon fuel.

The Formula

O2 (mol) = x + y/4, Air (mol) = O2 (mol) / 0.21

Worked Example

Methane, CH4 (x=1, y=4):

O2 = 1 + 4/4 = 2 mol, Air = 2 / 0.21 = 9.52 mol per mol of methane

How to Use This Calculator

  1. Enter the number of carbon atoms (x) in the fuel formula CxHy.
  2. Enter the number of hydrogen atoms (y).
  3. Click Calculate to get the molar oxygen and air requirement.

Related Calculations

Compare against the Stoichiometric Air Requirement Calculator, which works on a mass basis instead.