How to Calculate Stone Porosity

Stone porosity is the measurement of how much air is in a given piece of stone -- or how porous the stone is. Different kinds of stone have different properties, and some are much more or less porous than others. If you're remodeling your home, it can be extremely important to know the porosity of stones you're considering using. For instance, it would be a very bad idea to use extremely porous stone in your kitchen, as it stains easily and absorbs liquid. While measuring the exact porosity of a given piece of stone requires very expensive professional equipment, it's quite easy to find a ballpark porosity for the kinds of stone in question.

Find out how porous your stone is!
  1. Procure a small sample of the stone you would like to test.

  2. Measure your stone's dry weight. This can be done by placing it on a scale.

  3. Immerse your stone in water until it stays submerged.

  4. Obtain it's weight, and divide the difference of it's current weight and the original by the unit weight for water or 62.3 lb. per foot cubed. Obtain the volume of the the rock it self: The formula for this is base x base x height. Divide this number into the volume of the water. This will yield the porosity in percentage form.


  • This is only a ballpark figure, there are possibilities this test cannot take into account. If accuracy is a high priority, consider a professional evaluation.
Continue Reading