Clay Shrinkage Calculator

Estimate the final size of your clay creations after drying and firing, or calculate the wet dimensions needed for a specific finished size.

Common values: Earthenware 10-15%, Stoneware 12-14%, Porcelain 12-17%.

About Clay Shrinkage

Clay shrinks as water evaporates during the drying process and vitrifies during firing. Understanding shrinkage is crucial for potters who need their final pieces to be a specific size, such as fitting a lid to a jar or making a set of nested bowls.

Typical Shrinkage Rates

  • Earthenware: 10% - 15%
  • Stoneware: 12% - 14%
  • Porcelain: 12% - 17%
  • Air Dry Clay: 5% - 10%

Always test your specific clay body by making a shrinking ruler or test tile to determine its exact shrinkage rate.

How to use this calculator

To find Final Size: Enter your wet clay dimensions and the shrinkage percentage. The calculator will tell you how small the piece will become.

To find Required Wet Size: Switch the mode causing calculating backward. Enter the diverse TARGET final dimensions you want, and it will tell you how large to make the wet clay piece.