How much does it cost you to fire your kiln?
If your answer is "I don't know" or "a few bucks in electricity," you're underpricing your work. Every potter I've talked to can tell you the cost of a bag of clay and a pint of glaze off the top of their head. Almost none of them can tell you what a single firing actually costs when you add up electricity, element wear, kiln furniture replacement, and the occasional piece that cracks and becomes a $0 return on hours of labor.
That firing cost is the biggest blind spot in ceramic pricing. And it's not small. A typical cone 6 electric kiln firing runs $8–$25 in electricity alone, depending on your kiln size and local rates. Add element depreciation, kiln wash, posts, stilts, and maintenance — and you're looking at $15–$40 per firing in true costs. If you're fitting 15 pieces in a load, that's $1–$2.70 per piece in kiln overhead before you've accounted for a single gram of clay.
Let's fix that blind spot right now.
The Real Cost of Electricity Per Firing
Electricity is the largest kiln expense, and it's surprisingly easy to calculate once you know where to look.
Your kiln has a wattage rating — it's on the nameplate or in the manual. A common midsize kiln like a Skutt KM-1027 draws about 11,000 watts (11 kW). A cone 6 firing in that kiln takes roughly 8–10 hours. Your electricity rate is on your utility bill, listed as a per-kWh charge.
The formula:
Kilowatt rating × Hours × Price per kWh = Electricity cost per firing
| Kiln Size | Wattage | Cone 6 Time | At $0.12/kWh | At $0.18/kWh | At $0.25/kWh |
|---|---|---|---|---|---|
| Small (7 cu ft) | 8 kW | 8 hrs | $7.68 | $11.52 | $16.00 |
| Medium (10 cu ft) | 11 kW | 9 hrs | $11.88 | $17.82 | $24.75 |
| Large (13 cu ft) | 14.4 kW | 10 hrs | $17.28 | $25.92 | $36.00 |
That's just electricity. And notice the range — a potter in a state with $0.25/kWh rates (looking at you, California and Connecticut) pays more than double what someone in a low-rate state pays. Your location directly affects your cost of goods, and your prices need to reflect that.
One more thing people miss: bisque firings. Most pieces get fired twice — once to bisque (cone 06, around 6–7 hours) and once to glaze (cone 6, 8–10 hours). So the electricity cost per piece is really the sum of both firings divided by the number of pieces in each load. If your bisque and glaze loads aren't the same size — and they rarely are — you need to calculate them separately.
Bisque firing electricity (medium kiln at $0.15/kWh): 11 kW × 7 hrs × $0.15 = $11.55 Glaze firing electricity (same kiln): 11 kW × 9 hrs × $0.15 = $14.85 Total electricity for both firings: $26.40
If you fit 20 pieces in your bisque load and 15 in your glaze load, the per-piece electricity cost is ($11.55 ÷ 20) + ($14.85 ÷ 15) = $0.58 + $0.99 = $1.57 per piece.
Not "a few bucks." A dollar fifty-seven — per piece — just in electricity.
Element Replacement: The Cost Nobody Tracks
Kiln elements don't last forever. They degrade with every firing, gradually losing efficiency until your kiln can't reach temperature. Most potters replace elements when firings start taking noticeably longer — which means they've been paying for degraded performance (longer firing times = higher electricity costs) for months before they notice.
A typical set of elements for a midsize kiln costs $150–$300. If you replace them yourself, that's the whole cost. If you pay someone, add $100–$200 for labor.
How often? That depends on how hot you fire and how often. A reasonable estimate for cone 6 firings:
| Firing Frequency | Element Lifespan | Cost per Firing (DIY) | Cost per Firing (Pro Install) |
|---|---|---|---|
| 2 firings/week | ~100 firings | $2.00 | $3.50 |
| 1 firing/week | ~120 firings | $1.67 | $2.92 |
| 2 firings/month | ~150 firings | $1.33 | $2.33 |
So element wear adds another $1.33–$3.50 per firing. Divide that by the pieces per load and it's another $0.09–$0.23 per piece. Small? Sure. But it adds up across hundreds of pieces a year, and it's real money you're spending whether you track it or not.
Here's the uncomfortable part: if you're not tracking element age, you're also eating the cost of inefficiency. Old elements make firings run 1–2 hours longer. At $0.15/kWh with an 11 kW kiln, that's an extra $1.65–$3.30 per firing in electricity you didn't need to spend. Track your element age. Replace them on schedule, not when they fail.
Kiln Furniture, Wash, and Consumables
These are the costs that feel too small to track individually — and collectively represent a real line item.
Kiln shelves ($25–$60 each) last years but eventually warp or crack. If you have 6 shelves and replace one per year, that's $40/year ÷ your annual firing count.
Kiln posts and stilts ($0.50–$3 each) break or wear. Budget $2–$5 per firing in furniture consumables.
Kiln wash (a protective coating you brush on shelves to prevent glaze drips from bonding) costs about $15 per bag and lasts 20–30 firings. That's roughly $0.50–$0.75 per firing.
Pyrometric cones or a kiln sitter — if you use witness cones, they're about $0.30–$0.50 per firing. Digital controllers eliminate this cost but have their own repair/replacement cycle ($200–$400 every 5–10 years).
Thermocouple replacement — the temperature sensor in your kiln wears out every 2–4 years ($30–$80 to replace). Minor, but real.
Add it up:
| Consumable | Estimated Cost per Firing |
|---|---|
| Kiln furniture wear | $0.50–$1.00 |
| Kiln wash | $0.50–$0.75 |
| Witness cones | $0.30–$0.50 |
| Thermocouple (amortized) | $0.05–$0.10 |
| Total consumables | $1.35–$2.35 |
The Number That Actually Matters: Cost Per Piece
Now let's put it all together. Here's a realistic total for a medium kiln (10 cu ft), firing at cone 6, at $0.15/kWh, with 15 pieces per glaze load:
| Cost Category | Per Firing | Per Piece (15/load) |
|---|---|---|
| Electricity (bisque + glaze) | $26.40 | $1.57 |
| Element wear | $2.00 | $0.13 |
| Consumables | $1.85 | $0.12 |
| Total kiln cost | $30.25 | $1.82 |
$1.82 per piece. That's not clay, not glaze, not your time, not your studio rent. That's just what it costs to turn raw pottery into finished ceramics in the kiln.
For a mug that uses $1.50 in clay and $0.60 in glaze, the kiln just added 87% to your material cost. If you were pricing based on "about $2 in materials" and marking up 3x to $6, your actual material cost is $3.82 — and your real markup is only 1.6x. At $6, you might be losing money once you factor in any other overhead.
This is why potters who price "by feel" consistently underprice. The costs you can see (clay, glaze) are only half the picture.
What About Gas Kilns?
If you fire with propane or natural gas, the math changes but the principle doesn't. Gas kilns are generally cheaper per firing for large loads but have higher upfront and maintenance costs.
A rough comparison for a cone 10 reduction firing:
| Fuel Type | Cost per Firing (medium kiln) | Notes |
|---|---|---|
| Electric (cone 6) | $12–$25 electricity | Predictable, easy to calculate |
| Propane (cone 10) | $15–$40 fuel | Varies wildly with propane prices and efficiency |
| Natural gas (cone 10) | $8–$20 fuel | Cheapest per firing if available |
Gas kilns also require burner maintenance, flue cleaning, and more expensive structural repairs. The per-firing consumable cost is roughly similar to electric, but you should add $1–$3 per firing for gas-specific maintenance amortization.
The key point: whether you fire electric or gas, "I don't know what a firing costs" is not an acceptable answer if you're selling your work.
Building Kiln Costs Into Your Prices
Now that you have a per-piece kiln cost, work it into your pricing formula. Every piece you sell should cover:
- Clay cost — weight used × price per pound
- Glaze cost — estimated per piece (weigh a few to calibrate)
- Kiln cost — use your calculated per-piece number from above
- Other materials — underglazes, wax resist, stilts specifically for that piece
- Labor — your time at a rate you've chosen (if you haven't chosen one, that's a separate problem)
- Overhead — studio rent, tools, insurance, website, market fees, divided across your monthly output
- Margin — the profit above all costs that makes this a business, not an expensive hobby
Most pricing guides cover steps 1, 2, and 5. Steps 3, 4, and 6 are where potters consistently leave money on the table.
A tool like Ardent Seller can help here. You set up your clay, glaze, and kiln consumables as inventory, create a recipe for each product that includes exact material quantities, and the system calculates your true cost per piece — including the kiln costs most potters track on napkins or not at all. When propane prices spike or your electricity rate changes, you update one number and every product cost recalculates automatically.
Track It or Eat It
Here's what I want you to do this week. Just one thing.
Calculate your actual cost per firing. Pull up your last electricity bill. Look up your kiln's wattage. Time your next firing from start to finish. Multiply those three numbers together. Then add your best estimate for element wear and consumables using the tables above.
Write that number down. Divide it by the number of pieces in your last load.
That's your kiln cost per piece. Compare it to what you assumed it was. If you're like most potters, the real number is 2–3x what you had in your head — and that difference has been coming directly out of your profit on every single piece you've sold.
You don't need to overhaul your entire pricing today. But you do need to know this number. Because once you do, you'll stop setting prices based on what clay and glaze cost and start setting them based on what your work actually costs to produce. And that's the difference between a pottery business that grows and one that quietly subsidizes every customer's purchase with your unpaid labor.
If you want to get systematic about it, start tracking your costs in Ardent Seller — it's free for up to 20 transactions a month, which is plenty to get your kiln costs mapped out and your pricing dialed in.