Will It Shrink?

Clay moves the whole time it's in your hands — through drying and firing. Use this to plan your size before you even wedge the clay.

Wet (greenware) size

Any one measurement works — height, diameter, width, whatever you're tracking. Clay shrinks the same % in every direction, so pick one and stick with it.

Height (cm)

Rim diameter (cm)

Base diameter (cm)

Measured inside the walls, straight down from the rim. If your cup's sides are straight, make rim and base the same. → estimated capacity: 0ml

Clay body

Total shrinkage %

WET

FIRED

Fired size will be

8.75"

That's 12.5% smaller than what you're holding now.

Why it shrinks twice

Clay shrinks once as it dries, then again in the kiln. The percentage above is both combined — the full change from wet to fired.

Capacity shrinks faster than size

A cup shrinks in three directions at once — height, width, and depth — so it loses more space inside than you'd expect. At 12.5% shrinkage, it holds about a third less than before.

Every clay body is different

Different clays shrink by different amounts. The numbers above are averages — check your clay's bag for the exact rate, and test a small piece if precision matters.