The formula to calculate the Porosity Percentage (P) is:
\[ P = \left( \frac{V_v}{V_t} \right) \times 100 \]
Where:
Let's say the volume of voids is 30 units³ and the total volume is 100 units³. Using the formula:
\[ P = \left( \frac{30}{100} \right) \times 100 \]
We get:
\[ P = 30 \% \]
So, the porosity percentage is 30%.