How to use the rock porosity calculator
Compute porosity from bulk and grain density. Enter bulk density, grain density in the fields above; the porosity is computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- rb — Bulk density (g/cm³)
- rg — Grain density (g/cm³)
Worked example
With bulk density = 2.1 g/cm³, grain density = 2.65 g/cm³, the calculator gives porosity ≈ 20.75472 %.
Frequently asked questions
What is the formula for the rock porosity calculation?
Porosity (%) = 100 × (1-rb / rg). Here rb is bulk density (g/cm³), rg is grain density (g/cm³).
What inputs do I need for the rock porosity calculator?
You need bulk density in g/cm³, grain density in g/cm³. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.