Pricing Pottery By the Kiln Load, Not the Piece
Clay and glaze are the easy costs. The real math is what a kiln load costs when a fifth of it never makes the shelf. Worked example, to the penny.
You know what a bag of clay costs. You know what a jar of glaze costs, roughly, because you keep buying it. What most potters don't actually know — not to the penny — is what a piece costs once you count the kiln.
Not the electricity bill, though that's part of it. The kiln itself, as a cost center, does something no other part of pottery does: it destroys a chunk of your inventory on a schedule, and if you're pricing off "clay plus glaze," you're pricing off the load that never fails. That load doesn't exist. Ask any potter who's opened a glaze kiln to a shelf of dunted mugs or a glaze that pinholed across a whole batch — loss isn't the exception in this craft, it's a line item. Community wisdom puts it at something like 5 to 15 percent of a load lost to cracking, warping, or glaze defects, even for people who've been firing for years. That's not a rare bad day. That's Tuesday.
So here's the actual question: what does a mug cost you, once you count every mug that went into the kiln — not just the ones that came out?
The kiln load is the batch
Every other maker who batches product gets this instinctively. A candle maker knows a pour is a pour — wax, fragrance, wicks, one block of labor, divided across however many candles that pour makes. Pottery works the same way, it just has two firings instead of one production run, and the "batch" doesn't finish until the second kiln opening.
Greenware goes in as a headcount. Bisque comes out short a few. Glazed ware goes back in. Glaze fire comes out short a few more, plus a handful you'll sell as seconds instead of firsts. What you're left with — the actual sellable count — is the number every cost in that load has to be divided by. Not the number you started with.
That's the whole idea, and it's the same idea MadeKeeper's batch tool runs on for every craft that works in batches: log what went in, log what actually survived, and let the cost per piece be honest about the difference.
A kiln load, worked to the penny
Say you're throwing a load of 24 mugs — a full bisque kiln for a lot of home studios.
Clay. Each mug takes about a pound of clay, wet. A 25-lb bag of stoneware runs somewhere in the $25–$40 range depending on your clay body and supplier; call yours $32. That's $1.28 a pound, so 24 lb of clay costs $30.72 for the load.
Bisque firing. Say your kiln runs about $18 in electricity for a bisque load at cone 06 — a number that'll vary with your kiln, your utility rate, and your firing schedule, so use your own. Call it $18.00.
First loss. You open the kiln to two cracked mugs — a trimming flaw that didn't show until the fire. Down to 22.
Glazing. You dip-glaze the 22 survivors. Call your glaze cost $0.40 a mug in materials — that's $8.80 for the load.
Glaze firing. A cone 6 glaze fire runs hotter and longer than bisque; say $22.00 in electricity.
Second loss. One mug comes out with a glaze flaw bad enough to scrap. Two more are fine functionally but have a drip or a pinhole — they're seconds, not firsts. You're left with 19 firsts and 2 seconds, 21 sellable pieces from 24 you started.
Labor. Throwing, trimming, glazing, and loading/unloading two kilns for this load runs about 3 hours. If you're pricing your own time at $20 an hour, that's $60 for the load — priced in for what you charge, never counted as a tax cost, because your own labor isn't a deductible expense to the IRS even though it's very much a real cost to you.
Add it up: $30.72 clay + $18.00 bisque + $8.80 glaze + $22.00 glaze fire = $79.52 in hard, out-of-pocket cost for the load. Divided across 21 sellable mugs, that's $3.79 a mug before you've paid yourself a dime.
Now put labor back in for pricing purposes: $79.52 + $60.00 labor = $139.52, divided by 21 mugs, is $6.64 a mug fully loaded. That's the number that should be sitting under your price tag — not the $3.31 you'd get if you divided the same $79.52 across all 24 mugs you started with, pretending none of them broke.
The gap between those two numbers — $79.52 divided by 24 versus divided by 21 — is small on paper and real in your bank account. Run it across a year of kiln loads and it's the difference between a price that quietly subsidizes your kiln's bad days and one that doesn't.
Seconds aren't free inventory
Those two seconds mugs are worth naming separately, because they're not a rounding error — they're a pricing decision. A second costs you the same $6.64 to make as a first. If you sell it at half off because it has a drip, you're recovering about $3.32 against a $6.64 cost, and that gap has to come from somewhere: either your firsts are priced to cover it, or your seconds table is quietly running at a loss you've never actually looked at.
Neither answer is wrong. Plenty of potters run seconds tables at a loss on purpose, as a way to move stock and build goodwill at a fair. The problem isn't the discount — it's not knowing you're giving one, and by how much, load after load.
Why the online calculators undercount this
Most pottery pricing advice — including some genuinely good posts on pricing formulas — starts and ends with "materials plus labor plus overhead, times a multiplier." That math works fine for a potter who fires everything perfectly, which is to say, no potter. It treats a kiln load like a bag of beads: buy it, count it, sell it. Nothing breaks between the workbench and the shelf.
Two firings and a loss rate is exactly what makes ceramics different from most crafts on a materials sheet, and it's exactly what most of those formulas leave out. The fix isn't a different formula. It's counting the load the way it actually happens — go in with a headcount, come out with a smaller one, divide by what's left.
What this looks like without a spreadsheet
This is the same math MadeKeeper runs for every batch, whatever the craft: you log a "make" — clay, glaze, the materials your recipe calls for — as a batch, and when it's done you record what actually survived. The cost per mug comes out of the recipe automatically, labor gets amortized across whatever quantity you tell it came out sellable, and the suggested-price coach flags it if your price doesn't clear the cost. Two firings just means you're recording one batch with a kiln in the middle of it, not two separate systems to keep straight.
If you glaze anything for food contact, that's a records question, not a compliance claim from us — we're not going to tell you your glaze is food-safe, that call and the testing behind it are yours. What we'll do is keep the batch notes and lot numbers next to the piece, so if you ever need to point at what glaze, what lot, what firing a piece came from, it's already written down.
None of this needs to live in your head. It needs to live in a ledger that does the dividing for you — the one that already knows how many mugs went in and how many came out.
If you're still doing this on the back of an envelope, or in a Craftybase account that's drifted upmarket since it became Stocksmith, the whole point of switching is that the math above stops being something you do once a season and starts being something the tool already knows. MadeKeeper is free during the founding pilot, and it's built for potters running kiln loads out of one studio — not production floors. If you want to see how the rest of the trade maps onto it, from bisque to seconds to the tax packet, the pottery page lays out the whole shape.
Your kiln already knows how many pieces it destroyed this year. It's worth knowing what that cost you, to the penny, instead of to the nearest guess.