How to Use This Calculator
- 1
Enter your Kiln Size
Input the interior volume of your kiln in cubic feet. Larger kilns consume more electricity per firing.
- 2
Enter your Electricity Rate
Provide your utility cost per kilowatt-hour ($/kWh). Check your electricity bill for the exact rate; a typical US rate is $0.10–$0.16/kWh.
- 3
Set Bisque and Glaze Firing Temperatures
Enter the peak temperature in °F for each firing type. Typical bisque is 1,800–1,940 °F (cone 06–04); glaze firings range from 2,232 °F (cone 6) to 2,350 °F (cone 10).
- 4
Enter Average Firing Duration
Input how many hours a typical firing cycle takes from start to peak temperature.
- 5
Set Firings per Month
Enter how many bisque firings and glaze firings you run on average each month.
- 6
Review your results and insights
The calculator displays six cards: Annual Firing Cost ($), Bisque Cost / Firing ($), Glaze Cost / Firing ($), Glaze vs Bisque Ratio (x), Cost Difference ($), and Est. Savings if Batched ($). Below the main results, an 'Firing Cost Insights' panel provides a summary, key energy consumption metrics, and an annual cost breakdown.
Example Calculation
A pottery studio owner with a 7 cu ft kiln paying $0.12/kWh wants to compare their bisque and glaze firing electricity costs.
Kiln Size (cu ft)
7
Electricity Rate ($/kWh)
0.12
Bisque Firing Temp (°F)
1835
Glaze Firing Temp (°F)
2232
Average Firing Duration (hrs)
8
Bisque Firings per Month
4
Glaze Firings per Month
4
Results
Annual Firing Cost
$196.78
Bisque Cost / Firing
$1.85
Glaze Cost / Firing
$2.25
Glaze vs Bisque Ratio
1.22x
Cost Difference
$0.40
Est. Savings if Batched
$29.52
Tips
Reduce Costs by Batching Firings
Consolidating bisque or glaze loads reduces the number of firings per month. The calculator estimates a 15% savings potential from batching — for a studio spending $200/year, that's $29.52 back in your pocket.
Monitor Your Electricity Rate
Electricity rates vary by season and provider, sometimes doubling during peak hours. Using a time-of-use rate or firing overnight can cut your per-firing cost significantly, especially for glaze firings that can run 10+ hours.
Higher Temperatures Cost More
Each 100 °F increase in peak temperature noticeably raises kWh consumption. If your glaze work allows it, testing a lower-cone body (e.g., cone 6 instead of cone 10) can reduce your glaze firing cost by 5–10%.
Comparing Bisque and Glaze Firing Electricity Costs
For any ceramic artist running an electric kiln, electricity is the largest recurring operating expense.
The Bisque vs. Glaze Firing Cost Calculator estimates and compares the electricity cost of each firing type based on your kiln size, peak temperatures, firing duration, and how often you fire each month.
For example, a standard 7 cu ft kiln fired at cone 6 (2,232 °F) costs roughly $2.25 per firing at $0.12/kWh — a small number that compounds to nearly $108/year for a studio running four glaze firings per month.
The Formula Behind the Firing Cost Estimate
The calculator estimates kiln energy consumption using a rule-of-thumb formula that accounts for kiln volume, peak temperature, and firing duration.
The energy usage (kWh) is proportional to both kiln size and the temperature it must reach — larger kilns and hotter firings draw more power.
bisque kWh = kilnSize × (bisqueTemp / 1000) × 1.2 × firingHours / 8
glaze kWh = kilnSize × (glazeTemp / 1000) × 1.2 × firingHours / 8
The cost per firing is then simply the kWh times your electricity rate:
bisque cost per firing = bisque kWh × electricityRate
glaze cost per firing = glaze kWh × electricityRate
Annual costs are derived by multiplying the per-firing cost by the number of firings per month and by 12 months:
annual total = (bisqueCostPerFiring × bisqueFreq × 12) + (glazeCostPerFiring × glazeFreq × 12)
The ratio shows how much more expensive glaze firing is relative to bisque:
glaze vs bisque ratio = glazeCostPerFiring / bisqueCostPerFiring
And the estimated batching savings applies a 15% reduction to the annual total:
est. savings if batched = annualTotal × 0.15
Worked Example: 7 cu ft Kiln at $0.12/kWh
A pottery studio owner has a 7 cubic foot electric kiln and pays $0.12 per kWh.
They fire bisque at 1,835 °F and glaze at 2,232 °F, with an average firing cycle of 8 hours, and run 4 bisque and 4 glaze firings each month.
- Bisque kWh: 7 × (1835 / 1000) × 1.2 × (8 / 8) = 7 × 1.835 × 1.2 × 1 = 15.414 kWh
- Glaze kWh: 7 × (2232 / 1000) × 1.2 × (8 / 8) = 7 × 2.232 × 1.2 × 1 = 18.7488 kWh
- Bisque Cost / Firing: 15.414 × $0.12 = $1.85 (rounded from $1.84968)
- Glaze Cost / Firing: 18.7488 × $0.12 = $2.25 (rounded from $2.249856)
- Annual Bisque Cost: $1.84968 × 4 × 12 = $88.78 (rounded from $88.78464)
- Annual Glaze Cost: $2.249856 × 4 × 12 = $107.99 (rounded from $107.993088)
- Annual Firing Cost: ($1.84968 × 4 × 12) + ($2.249856 × 4 × 12) = $88.78464 + $107.993088 = $196.777728 ≈ $196.78
- Glaze vs Bisque Ratio: $2.249856 / $1.84968 = 1.21639 ≈ 1.22x — glaze costs 22% more per firing
- Cost Difference: $2.249856 − $1.84968 = $0.400176 ≈ $0.40 per firing
- Est. Savings if Batched: $196.777728 × 0.15 = $29.5166592 ≈ $29.52
This studio spends about $196.78 per year on kiln electricity, and could save roughly $29.52 by consolidating partial loads into full firings.
Practical Application Context
Understanding per-firing electricity costs helps ceramic studios make better operational decisions.
A studio running many small bisque loads can often batch two half-loads into one full load, cutting bisque firings in half and saving $50–$100 per year with no change in output.
For studios considering upgrading to a larger kiln, this calculator can model the trade-off: a 10 cu ft kiln costs more per firing, but if it allows fewer total firings, the annual cost may actually decrease.
Glaze firing temperatures also matter strategically — artists who can achieve their desired surface at cone 6 rather than cone 10 will see a meaningful reduction in electricity cost for every glaze firing they run.
How professionals interpret bisque vs. glaze firing cost output
Experienced ceramicists and studio managers look at the Glaze vs Bisque Ratio first.
A ratio near 1.0x means bisque and glaze firings cost about the same — unusual and worth investigating (it might mean bisque temperatures are set too high).
A ratio of 1.2x–1.4x is typical, reflecting the difference between cone 04 and cone 6 temperatures.
Ratios above 1.5x often indicate that glaze firings are reaching cone 9–10, and the studio may want to explore whether lower-fire glazes could achieve similar results.
The Annual Firing Cost is then compared against studio revenue — for a working production potter, kiln electricity should represent no more than 3–5% of gross revenue.
If it climbs above that, it signals either under-pricing, over-firing, or inefficient kiln loading.
The Est.
Savings if Batched number is treated as a planning benchmark: if the potential savings exceed the hassle of holding work to fill a kiln, batching is worth the scheduling adjustment.
Frequently Asked Questions
Why does glaze firing cost more than bisque firing?
Glaze firings typically reach higher peak temperatures (e.g., 2,232–2,350 °F for cone 6–10) compared to bisque firings (1,800–1,940 °F for cone 06–04). Since the calculator estimates kWh as proportional to peak temperature, a higher target temperature directly increases electricity consumption and cost per firing.
How accurate is the kWh estimate in this calculator?
The calculator uses a rule-of-thumb formula: kWh ≈ kilnSize (cu ft) × (peakTemp / 1000) × 1.2 × (firingHours / 8). This provides a reasonable ballpark for electric kilns but actual consumption depends on kiln insulation quality, ambient temperature, and how tightly the kiln is loaded. Always compare against your electricity meter readings for precision.
What does 'Est. Savings if Batched' mean?
This is a 15% reduction applied to the annual total cost, representing the estimated savings you could achieve by consolidating firings — for example, combining two half-full bisque loads into one full load. For the example scenario, this is $29.52. It is an approximation; actual savings depend on how well you can fill each firing.
How do I lower my annual kiln electricity cost?
The most effective levers are: (1) fire at the lowest temperature your work allows, (2) fully load the kiln before every firing, (3) fire during off-peak electricity hours if your utility offers time-of-use rates, and (4) check kiln elements and lid seals regularly — worn elements and poor insulation increase energy draw significantly.