Clay Shrinkage Calculator
Estimate finished clay size after drying and firing, or work backwards to find the wet size you need before shrinkage.
This is useful for pottery, ceramic tiles, sculpture, and any project where clay shrinkage matters to the final fit.
Result
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Run the calculation to see the clay size estimate.
Quick Answer
Dry size equals wet size multiplied by one minus the shrinkage percentage, so the material loses a predictable fraction as it dries or fires.
How to Use It
- Select whether you want the finished dry size or the required wet size.
- Enter the known size and the shrinkage percentage.
- Choose your preferred unit.
- Click Calculate to see the result.
Formula
Dry size = wet size x (1 - shrinkage percentage / 100)
Wet size = dry size / (1 - shrinkage percentage / 100)
Worked Examples
Example 1: A 20 cm wet piece with 12% shrinkage dries to 17.6 cm.
Example 2: To finish at 30 cm with 15% shrinkage, the wet size must be about 35.3 cm.
Example 3: The same formula works for width, height, or thickness if shrinkage is uniform.
How to Interpret Your Results
| Output | Meaning | Action |
|---|---|---|
| Dry size | The expected finished dimension after shrinkage. | Use this for fit checks and final measurements. |
| Wet size required | The starting dimension before shrinkage. | Use this when building to a final target. |
| Shrink amount | The difference between wet and dry dimensions. | Allow enough clay to cover that loss. |
Frequently Asked Questions
Related Calculators
References
- OmniCalculator reference page
- The calculator assumes uniform shrinkage across the chosen dimension.
- Last reviewed: March 2026.