Free calculator
Soil moisture content calculator (ASTM D2216)
Enter the container mass, the container plus wet soil, and the container plus oven-dry soil, all in grams. The calculator returns the mass of water, the mass of dry soil and the moisture content as a percent of dry mass.
By ProofGrit Editorial TeamLast reviewed:
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Key takeaways
- w = (wet + container − dry + container) ÷ (dry + container − container) × 100.
- Moisture is based on dry mass, so it can exceed 100 %.
- Report moisture to 0.1 %.
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How it's calculated
How is the result calculated?
w = (container + wet − container + dry) ÷ (container + dry − container) × 100.
- 01Mass of water = (container + wet soil) − (container + dry soil)
- 02Mass of dry soil = (container + dry soil) − container
- 03Moisture content w = mass of water ÷ mass of dry soil × 100, reported to 0.1 %
- 04Standard drying oven temperature: 110 ± 5 °C
Rounding: moisture content, liquid limit, plastic limit and plasticity index to 0.1. Full precision is kept between steps.
FAQ
Frequently asked questions about the soil moisture content calculator
Is moisture content based on wet or dry mass?
Dry mass. Water mass is divided by the mass of oven-dry soil, so values above 100 % are possible for very wet soils.
What oven temperature is used?
The standard drying temperature is 110 ± 5 °C. Dry to constant mass as the current standard describes.
Can the container mass be zero?
Yes, if you tared the balance with the container. Enter 0 and use net masses.
Why does the calculator reject my numbers?
Dry mass must exceed the container mass, and wet mass cannot be less than dry mass. Check the weighings.
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- Sand cone test: ASTM D1556 procedure and calculationsHow the sand cone field density test works, the four-step calculation from sand in the hole to dry density, and the habits that keep results repeatable.
- Nuclear density test: field compaction with ASTM D6938How the nuclear gauge test works, the dry density and percent compaction math, the daily standard count check, and the mistakes that cause retests.
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- Standards indexEvery standard explained on this site, with plain-English purpose.
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Sources and further reading
- ASTM D2216, laboratory water (moisture) content of soil and rock by massASTM International
- ASTM D698, laboratory compaction using standard effortASTM International
- ASTM InternationalASTM International
Standards are summarized in our own words. Read the current edition from the publisher before you test.
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