# Air–fuel Ratio

Written by Jerry Ratzlaff on . Posted in Fluid Mechanics

Air–fuel ratio is the mass ratio of air to fuel mixture present in an internal combustion engines.

## formula

$$AFR = \frac {m_a} {m_f}$$

Where:

$$AFR$$ = air–fuel ratio

$$m_a$$ = air mixture

$$m_f$$ = fuel mixture