Air-Fuel Ratio (AFR) Calculator
Calculate air-fuel ratio for combustion reactions using fuel composition and stoichiometry.
Enter Parameters
1.0 = stoichiometric, <1.0 = rich, >1.0 = lean
Results
Enter parameters to calculate air-fuel ratio
Air-Fuel Ratio Concepts
Key Definitions
- • AFR: Mass ratio of air to fuel
- • Stoichiometric: Perfect combustion ratio
- • Lambda (λ): AFR/Stoichiometric AFR
- • Rich: λ < 1.0 (excess fuel)
- • Lean: λ > 1.0 (excess air)
Applications
- • Internal combustion engines
- • Gas turbines
- • Furnaces and boilers
- • Rocket propulsion
- • Industrial processes
Common Air-Fuel Ratios
Automotive Fuels
- • Gasoline: 14.7:1
- • Diesel: 14.5:1
- • E85 Ethanol: 9.8:1
- • Methanol: 6.4:1
Gaseous Fuels
- • Methane: 17.2:1
- • Propane: 15.6:1
- • Hydrogen: 34.3:1
- • Natural Gas: 17.2:1
Engine Conditions
- • Idle: 12-13:1 (rich)
- • Cruise: 14.7:1 (stoichiometric)
- • WOT: 12-13:1 (rich)
- • Lean burn: 16-18:1