How much clay do I need for a mug?

A standard mug (10cm tall, 8cm diameter) needs approximately 350–500g of clay depending on wall thickness and clay type. Stoneware is denser and needs more weight than earthenware. Always weigh out 15–20% extra for trimming waste and the foot ring.

How much does clay shrink when fired?

Stoneware shrinks about 12% from wet to fired, earthenware about 8%, and porcelain about 15%. This means you need to throw your pieces larger than the desired finished size. A 10cm wet mug becomes about 8.5cm in porcelain after firing.

Does wall thickness matter for weight?

Yes, significantly. Thin-walled pieces (4–5mm) use much less clay than thick-walled pieces (8–10mm). Beginner potters tend to throw thicker walls, so should start with more clay. As your skills improve, you will use less clay per piece.

How do I account for trimming waste?

Add 15–20% to the calculated clay weight for trimming waste. When you trim the foot ring and refine the shape on the wheel, you remove clay. Reclaim the trimmings by drying, slaking and wedging them for reuse.

CraftCalcs

Clay Weight Calculator \u2014 Pottery Forms

Calculate clay weight needed for common pottery forms including bowls, mugs, plates and vases.

Pottery Form

Select a form or choose custom

Clay Type

Type of clay body

Height

Height of the piece (wet)

Diameter

Outer diameter (wet)

Quantity

Number of pieces to make

Clay Price (optional)

Price per kg for cost estimate

How We Calculate This

This calculator estimates clay weight by calculating the volume of clay in a hollow cylindrical form (the wall and base), then multiplying by the clay density.

Volume formula

Clay volume = Outer cylinder volume \u2212 Inner cavity volume

Weight = Volume × Clay density

Clay densities

Stoneware: 1.8 g/cm\u00b3
Earthenware: 1.7 g/cm\u00b3
Porcelain: 1.9 g/cm\u00b3
Air-dry: 1.5 g/cm\u00b3

Frequently Asked Questions

Related Calculators

Glaze Thickness Calculator

Calculate number of glaze coats and total glaze volume needed for a piece based on surface area.

Shrinkage Calculator

Calculate wet clay dimensions needed to achieve desired finished size after firing shrinkage.

Kiln Loading Calculator

Calculate kiln shelf usage, pieces per firing and electricity cost per firing.

Last updated: March 2026

All calculations are estimates. Always verify quantities before purchasing materials.