The loss on ignition is illustrated by the image below.

To compute for loss on ignition, two essential parameters are needed and these parameters are **Weight before Firing (m _{1})** and

**Weight after Firing (m**

_{2}).The formula for calculating loss on ignition:

LOI = 100(^{(m1 – m2)}/m_{1})

Where:

LOI = Loss On Ignition

m_{1} = Weight before Firing

m_{2} = Weight after Firing

Let’s solve an example;

Find the loss on ignition when the weight before firing is 22 and the weight after firing is 11.

This implies that;

m_{1} = Weight before Firing = 22

m_{2} = Weight after Firing = 11

LOI = 100(^{(m1 – m2)}/m_{1})

LOI = 100(^{(22 – 11)}/_{22})

LOI = 100(^{11}/_{22})

LOI = 100(0.5)

LOI = 50

Therefore, the **loss on ignition **is **50%.**