Clay Moisture Content Calculator
Clay & Shrinkage
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Clay Moisture Content Calculator
Measure clay moisture percentage from wet and dry weights, or calculate how much water to add or remove to reach a target working consistency.
Reviewed by ClayCalc Editorial · Updated
Dry at 110°C until weight is stable.
Typical throwing: 18–22%.
Results
Enter your measurements above and click Calculate.
What is Clay Moisture Content?
Moisture content is expressed as a percentage of the total wet weight lost to water. At throwing consistency, clay contains roughly 18–22% water. Leather-hard clay is 12–18%, and bone-dry clay is under 1%.
Formula (Measure Mode)
Moisture % = (Wet weight − Dry weight) / Wet weight × 100
Formula (Adjust Mode)
When adjusting to a target moisture, the dry clay mass remains constant:
Dry clay (g) = Wet weight × (1 − current moisture / 100) Target wet weight = Dry clay / (1 − target moisture / 100) Water to add/remove = Target wet weight − Current wet weight
Working State Reference
| Moisture % | State | Typical Use |
|---|---|---|
| <1% | Bone dry | Ready to bisque fire |
| 8–12% | Leather hard (firm) | Trimming, handle attachment |
| 12–18% | Soft leather hard | Faceting, joining |
| 18–22% | Throwing consistency | Wheel throwing |
| 22–27% | Soft | Hand-building, coiling |
How to Measure Accurately
Weigh your sample on a digital scale (0.1g precision). Dry the clay at 110°C in an oven until weight stabilises (usually 2–4 hours depending on thickness). Re-weigh and apply the formula above.
Method & review note
About this calculation
Uses measured dimensions or weights and a stated arithmetic model. Clay and forming method vary, so production decisions should use test pieces from the actual body and firing.
Reference: Digitalfire — Drying Shrinkage. See the editorial methodology for testing, precision and corrections.
Input handling: Values are sent to the ClayCalc server for this request and are not written to the application database.