Enter the total volume of voids and the total volume of the soil into the Void Ratio Calculator. The calculator will evaluate and display the Void Ratio. 

Void Ratio Formula

The following formula is used to calculate the Void Ratio. 

n = VV / VS *100
  • Where n is the Void Ratio (%)
  • VV is the total volume of voids 
  • VS is the total volume of the soil 

To calculate the void ratio, divide the total volume of voids by the total volume of soil.

How to Calculate Void Ratio?

The following example problems outline how to calculate Void Ratio.

Example Problem #1:

  1. First, determine the total volume of voids.
    • The total volume of voids is given as: 40.
  2. Next, determine the total volume of the soil.
    • The total volume of the soil is provided as: 80.
  3. Finally, calculate the Void Ratio using the equation above: 

n = VV / VS *100

The values given above are inserted into the equation below and the solution is calculated:

n = 40 / 80 *100 = 50 (%)

FAQ

What is the significance of the void ratio in soil mechanics?
The void ratio is a critical parameter in soil mechanics as it helps in determining the porosity of the soil, which in turn affects the soil’s ability to retain water and its strength. A higher void ratio indicates more voids or spaces within the soil, which can influence the soil’s stability and its suitability for construction projects.

How does the void ratio affect soil compaction?
The void ratio directly impacts soil compaction. A lower void ratio means that the soil particles are closer together, which can lead to higher soil compaction. This is desirable in construction projects where a stable and firm foundation is required. Conversely, a higher void ratio indicates less compaction, which might be suitable for agricultural purposes where water drainage and root penetration are important.

Can the void ratio change over time?
Yes, the void ratio of soil can change over time due to various factors such as the type of soil, the amount of water it is exposed to, and the load applied to the soil. For example, heavy rainfall can increase the void ratio by washing away finer soil particles, while the application of a heavy load (like a building) can decrease the void ratio by compressing the soil particles closer together.