Lambda from AFR Calculator

A universal way to describe mixture regardless of fuel

Raw AFR numbers differ by fuel type (gasoline's stoichiometric AFR is about 14.7, while other fuels differ significantly), making direct AFR comparisons across fuels confusing - lambda normalizes this into one universal scale.

Worked example

For an actual AFR of 15.5 against a stoichiometric AFR of 14.7:

lambda = 15.5 / 14.7 = lambda = 1.0544 (Lean mixture)

Lambda Value	Mixture Classification
Below 1.0	Rich (more fuel than stoichiometric)
Exactly 1.0	Stoichiometric
Above 1.0	Lean (more air than stoichiometric)

Because lambda 1.0 always means stoichiometric regardless of the specific fuel, it is the standard reference engineers and engine control systems use to compare mixture ratio across different fuel types on one consistent scale.