Clay & Shrinkage

Wheel Throwing Weight Calculator

Calculate how much wet clay you need to throw a cylinder, mug, bowl, plate, or vase based on target dimensions and wall thickness.

Updated

Typical thrown wall: 6–10mm.

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Results

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Enter your measurements above and click Calculate.

How Much Clay Do I Need?

The weight of clay needed to throw a vessel depends on the form geometry (wall area × wall thickness × clay density) plus a waste allowance for centering clay and trimming.

Geometric Model

Wet throwing clay has a density of approximately 1.75 g/cm³. The calculator models each vessel as its geometric equivalent:

  • Cylinder / Mug: Cylindrical wall + flat base disc
  • Bowl: Partial hemisphere wall + foot ring area
  • Plate: Short rim ring + floor disc
  • Vase: Tapered cylinder (average radius 85% of rim)

Waste Factors by Form

FormWaste FactorReason
Cylinder15%Low trim waste
Mug20%Handle + trimming
Bowl18%Foot ring trimming
Plate22%Wide centering waste
Vase22%Tall form, neck shaping

Quick Reference (standard dimensions)

FormTypical dimensionsClay needed
Espresso cup6cm H × 6cm D~150g
Standard mug10cm H × 9cm D~350–450g
Dinner bowl8cm H × 18cm D~600–800g
Side plate2cm H × 22cm D~500–700g

Results are estimates. Actual amounts vary by thrower efficiency and clay body density.

Frequently Asked Questions

How much clay do I need for a standard mug? expand_more
A standard 350mL mug (9cm tall, 9cm diameter, 8mm wall) typically requires 350–450g of wet clay including trimming and centering waste. This calculator gives you the exact figure for your specific dimensions.
Why is more clay needed than the finished piece weighs? expand_more
The "waste factor" accounts for clay left on the wheel head during centering, trimming waste during leather-hard stage, and minor losses. Typically 15–22% extra is needed depending on vessel type.
Does wall thickness have a big effect on clay weight? expand_more
Yes — significantly. A mug with 10mm walls uses roughly 50% more clay than the same mug with 6mm walls. Experienced throwers naturally reduce wall thickness over time, using less clay for larger pieces.
Should I include a handle in the calculation? expand_more
Yes. The calculator adds approximately 60g for a standard pulled handle on a mug. Purists who weigh handles separately can deduct this from the total.