How do you calculate ceramic firing loss?

Multiply pieces lost by the fully loaded cost per fired piece and the allocation share, then add fixed costs. With 1200 pieces at $2.75, 100% allocation, plus $650 fixed, the allocated loss is $3,300 and the total is $3,950.

What counts as a firing loss in a kiln?

Any piece that fails during firing or unloading: thermal cracks, dunting, bloating, glaze defects, warping, and breakage from thermal shock or careless setting. It is post-firing scrap that has already consumed a full kiln cycle.

Why is firing loss more expensive than green-body loss?

A green reject only loses raw material and a little forming labor. A fired reject has absorbed clay, glaze, forming, drying, and a complete firing cycle of kiln energy, so the loaded cost per piece is much higher, which is why this calculator uses the cost per fired piece.

What is a good firing loss rate for ceramics?

It varies by product. Technical ceramics and large slabs may run higher, while standard tableware lines often target under 3-5% firing loss. The dollar figure matters more than the percent when pieces are expensive.

How does the allocation share work?

If the firing loss is shared across products or you only want to charge part of it to one kiln or order, set the allocation percent below 100. At 100% the full loss is assigned, giving $3,300 allocated here before fixed costs.

Firing loss vs scrap rate?

Scrap rate is a percentage of units; firing loss is the dollar impact of the fired scrap plus handling. Two lines with the same scrap rate can have very different firing losses if their fired piece costs differ.

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Ceramic Firing Loss Calculator

Ceramic firing loss is the dollar cost of pieces that crack, warp, dunt, or otherwise fail during firing and kiln unloading, plus the fixed cost of sorting, reworking, and disposing of them. Because a fired piece has already absorbed clay, glaze, forming labor, and a full kiln cycle of energy, a loss after firing is far more expensive than a green reject. Quality engineers and plant accountants use this number to justify kiln-loading changes, glaze reformulation, or slower cooling curves. It puts a hard currency value on what is often dismissed as normal yield loss.

What this calculator does

Estimate the cost of ceramic ware lost during firing, cooling, unloading, or kiln inspection.
a ceramic plant needs to cost kiln-related scrap for a product, firing cycle, or line
It computes total firing loss cost by multiplying lost pieces by cost per piece and an allocation share, then adding fixed sorting, rework, and disposal cost.

Formula used

Allocated ceramic firing loss = pieces lost during firing or kiln unloading × cost per fired piece lost × allocation share
Ceramic Firing Loss = allocated cost + fixed cost

Inputs explained

Pieces lost during firing or kiln unloading:
Cost per fired piece lost:
Firing loss assigned to this product or kiln:
Fixed kiln sorting, rework, or disposal cost:

How to use the result

Use it after a firing run or over a reporting period to cost out kiln losses and build the business case for process changes.
The cost per fired piece must reflect fully loaded value at the kiln exit; using only material cost will badly understate the loss.

Current U.S. benchmarks

U.S. housing starts run at 1,177k per year (Census, May 2026), down 8.7% from a year earlier, the demand driver for building products.
Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate ceramic firing loss? Multiply pieces lost by the fully loaded cost per fired piece and the allocation share, then add fixed costs. With 1200 pieces at $2.75, 100% allocation, plus $650 fixed, the allocated loss is $3,300 and the total is $3,950.
What counts as a firing loss in a kiln? Any piece that fails during firing or unloading: thermal cracks, dunting, bloating, glaze defects, warping, and breakage from thermal shock or careless setting. It is post-firing scrap that has already consumed a full kiln cycle.
Why is firing loss more expensive than green-body loss? A green reject only loses raw material and a little forming labor. A fired reject has absorbed clay, glaze, forming, drying, and a complete firing cycle of kiln energy, so the loaded cost per piece is much higher, which is why this calculator uses the cost per fired piece.
What is a good firing loss rate for ceramics? It varies by product. Technical ceramics and large slabs may run higher, while standard tableware lines often target under 3-5% firing loss. The dollar figure matters more than the percent when pieces are expensive.
How does the allocation share work? If the firing loss is shared across products or you only want to charge part of it to one kiln or order, set the allocation percent below 100. At 100% the full loss is assigned, giving $3,300 allocated here before fixed costs.

Last reviewed 2026-05-12.