Clay Shrinkage Calculator

Clay is a form of soil made up of tiny particles of aluminum silicate. When moist, clay is malleable, and when it dries, it becomes hard and brittle, and you cannot mold it anymore. Clay is widely used as a material for bricks, tiles, and pottery.

When making pottery, remember that the final size will differ from what you've sculpted - it will be smaller. It's because of the clay shrinkage phenomenon.

Clay shrinkage is the process of shrinking the clay when it dries out. While drying, the water particles evaporate from the original mass, and the whole object becomes smaller. Clay shrinkage applies to all types of clay — regular clay, metal clay, and air dry clay.

Regular clay will shrink by 10%-20%. In metal clays, it strongly depends on the type and kind of the clay and varies from 5% to even 30%. Air-dry clay shrinkage has the narrowest range — the object will get 8%-12% smaller.

Follow the steps:

1. Measure your clay object before it dries out. We need all three dimensions — height, width, and length.

2. Fill in the first three calculator rows with your measurements. Keep in mind that even though the basic unit is centimeters, you can change it to the most convenient unit.

3. Now, put in the clay shrinkage percentage. It describes how much the ready objects will be smaller than the original ones. Regular clay has a 10%-20% shrinkage level, air dry clay — about 8%-12%. Metal clay shrinkage depends on the particular kind - check out the metal clay shrinkage chart to find the type you've used.

4. Let the clay shrinkage calculator compute the results for you.

5. That's done! You know what the dimensions of your object will be after you cure it.

If you want to estimate the final dimensions on your own, here's the appropriate formula to calculate shrinkage in clay:

where:

• dimensiondimension — Length, width, and height of your object after curing;
• original dimensionoriginal dimension — Length, width, and height of your object before it's cured — so this is what you've actually measured; and
• CSCS — Clay shrinkage percentage, expressed in percents (%), not as a fraction.

Move on to the How do I calculate 14 percent shrinkage on clay? question in our FAQ section to see how to put the formula to work.

Metal clay consists of metal particles (metals such as silver, gold, bronze, and copper) combined with water and an organic binder. We use metal clay mainly to make jewelry. When you fire metal clay objects in a kiln, the binder burns away, leaving pure metal particles.

Metal clay jewelry will shrink while burned as well. The level of shrinkage depends on the material used. Check the metal clay shrinkage chart for precise levels.