Scale a known recipe, not a suggested clay body
Enter your own dry clay-body recipe. In parts mode, 5:3:2 and 50:30:20 describe the same proportions. In percentage mode, base entries must total 100%; the tool will not silently fill a missing percentage. Zero entries are allowed, but at least one base amount must be positive.
Add grog, stains or other materials to the base section if your source recipe includes them within its base total. Use the separate additions section only when the recipe explicitly gives an amount per 100 dry parts of base. Do not enter one ingredient in both sections.
Base batch or complete dry batch?
The target selector makes the denominator explicit. A base-only target is the weight before extra additions. A complete dry mix target includes the additions; the tool first reduces the base mass so everything fits that total. Neither target includes water, container weight, mixing losses or evaporation.
“2% extra” changes what a 1 kg target means
base = 1,000 ÷ 1.02 ≈ 980.3922 g
addition ≈ 19.6078 g
Method and worked example
Let P be the sum of base parts, pᵢ one base entry, aⱼ an extra addition in parts per 100 base, A the sum of these addition rates, and B the dry base mass.
Base ingredient mass = B × pᵢ ÷ P
Extra addition mass = B × aⱼ ÷ 100
Complete dry mass = B × (1 + A ÷ 100)
For a complete-mix target T: B = T ÷ (1 + A ÷ 100)
For a 1,000 g base in a 50:30:20 ratio, weigh 500 g, 300 g and 200 g. A separate 2-per-100-base addition weighs 20 g, so the dry total is 1,020 g. The prefilled material names and numbers are placeholders, not a tested clay formulation. With no extra additions, the base-only and complete-mix target modes are identical.
Units, weighing and rounding
Choose grams, kilograms, ounces or pounds by mass. Changing the unit converts the target and scale-readability input while retaining the same physical mass. One pound is 453.59237 g; one avoirdupois ounce is 28.349523125 g. These are not fluid ounces, cups or bulk-volume measures.
Outputs show up to four decimal places; computations use unrounded values. The displayed-row total and rounding difference help reveal display drift. This is not a claim of measurement accuracy. The optional scale-readability check flags nonzero ingredient masses smaller than one scale division; it cannot validate a scale, prescribe a suitable tolerance or guarantee that larger masses are accurately weighed. Tare containers and use equipment suitable for the smallest ingredient.
What this calculator does not decide
- It does not invent or validate a clay recipe, suggest substitutions, or adjust for differing chemical analyses, supplier materials or loss on ignition.
- It assumes all recipe entries are on the same dry-mass basis. Moist reclaim and wet commercial clay contain water; their as-received mass is not automatically interchangeable with dry powder. Measure moisture content separately if needed.
- It does not estimate water demand or choose an optimal moisture level. Working consistency depends on the materials and process.
- It does not establish plasticity, firing suitability, vitrification, glaze fit, strength or food safety. Make and evaluate appropriate small tests before scaling production.
- Dry ceramic materials may create hazardous dust. Follow supplier safety data and suitable studio dust-control procedures; this page is not a mixing or safety protocol.
Recipe names and quantities are used only in this page's memory. The calculator does not save or send them. Reloading loses your entries.
Sources and calculation boundaries
Glazy's calculator guide distinguishes normalizing every ingredient to 100 from a 100-part base with additional materials on top. Glazy's mixing-tests guide explains unit-independent batch multiplication, additions beyond the base and scale-resolution limits. These sources discuss ceramic glaze workflows; this tool uses the same proportional dry-mass arithmetic for a user-supplied clay-body recipe, not their glaze preparation or water instructions. The formulas above follow directly from those mass ratios. No source has independently reviewed or endorsed this tool.