Formula Used
- θv is volumetric moisture content.
- Vw is water volume in cubic centimetres.
- Vt is total sample or soil volume.
- ρb is dry bulk density.
- ρw is water density.
How to Use
- Select the calculation method matching your available data.
- Enter measurements and choose the correct units.
- Add porosity, field capacity, or wilting point when available.
- Choose the preferred secondary output unit and precision.
- Select Calculate moisture to view results and warnings.
- Copy, print, or export the completed calculation report.
Example Data
| Method | Input values | Expected volumetric moisture |
|---|---|---|
| Direct volume | 25 cm³ water, 100 cm³ total volume | 0.25 cm³/cm³ or 25% |
| Wet and dry mass | 125 g wet, 100 g dry, 100 cm³ sample, 1 g/cm³ water | 0.25 cm³/cm³ or 25% |
| Gravimetric conversion | 20% gravimetric moisture, 1.30 g/cm³ bulk density | 0.26 cm³/cm³ or 26% |
Frequently Asked Questions
What is volumetric moisture content?
It is the water volume divided by total sample volume. The decimal value uses units of cm³/cm³. Multiply it by one hundred to obtain percentage.
Are cubic centimetres and millilitres equivalent?
Yes, one cubic centimetre equals one millilitre. The calculator treats both units identically. Choose either label that matches your measurement source.
How does the wet-and-dry method work?
The dry mass is subtracted from wet mass. That difference represents the water mass. Water density converts the mass into water volume.
What water density should I enter?
A common laboratory estimate is 1.00 g/cm³. Temperature and dissolved materials can alter density. Enter a measured value when higher precision matters.
Can volumetric moisture exceed 100 percent?
It normally should not exceed total sample volume. Excessive results often indicate incorrect units or measurements. The calculator displays a warning when this occurs.
What is degree of saturation?
Saturation compares volumetric moisture with total porosity. One hundred percent means all pore space contains water. Values above that level require input verification.
What is air-filled porosity?
Air-filled porosity equals total porosity minus water content. It estimates pore space currently occupied by air. Negative values indicate water exceeds entered pore volume.
How is additional water calculated?
The calculator subtracts current moisture from target moisture. It multiplies that difference by total material volume. Negative results indicate water removal may be required.
Can area and depth define soil volume?
Yes, target mode supports area multiplied by depth. The result is converted into cubic centimetres internally. This helps estimate irrigation water across larger zones.
What is plant-available water capacity?
It is field capacity minus permanent wilting point. Multiplying this difference by volume gives stored water. Actual plant access also depends on roots and soil.
Can I compare several samples?
Yes, enter comma-separated sample rows in the comparison box. Each row needs a name and two volumes. The calculator displays moisture values in one table.