This page provides a set of calculators to help with calculating common material substitutions in glaze recipes.

Warning: These calculators are based on theoretical UMF analysis of the materials, and I have not verified them experimentally. Oxide analysis isn’t the only factor that determines how a material will behave in a glaze.

Each calculator allows for conversions between two material forms. Click “Switch” to toggle the conversion direction. Red cells indicate that a material should be subtracted from the recipe.

Wollastonite / Whiting


Bone Ash / Dicalcium Phosphate

Bone ash (TCP)
Dicalcium phosphate

Copper Carbonate / Black Copper Oxide

Copper carbonate
Black copper oxide

Cobalt Carbonate / Cobalt Oxide

Cobalt carbonate
Cobalt oxide

Manganese Carbonate / Manganese Dioxide

Manganese carbonate
Manganese dioxide