For Potters By Potters
Clay Shrinkage Calculator
Clay shrinks as it dries and fires. Use this free calculator to size your greenware up so it comes out right.
Size your piece up now so it comes out right later — or measure a test tile to find your clay's true rate.
Target finished (fired) size
in
in
Build it this big while wet
Width
2.84 in
(2 13/16″ on a ruler)
Height
3.98 in
(4″ on a ruler)
Scratch a line exactly 100 mm (or any length) into a flat test tile of your clay. Fire it the way you normally would, then measure the same line. Enter both below.
mm
mm
Your clay's shrinkage rate
12.0%
(wet − fired) ÷ wet — just measure both the same way.