What Does It Actually Cost to Fire a Kiln?

Electricity is one of the ongoing costs of running a studio, and it's also one of the hardest to see clearly. Clay comes in bags with a price on the side. Glaze materials are weighed and measured. But a firing draws its power quietly over many hours, and it arrives on a bill combined with everything else in the building, which makes it difficult to know what any individual load actually cost you.

The Ecotop Firing Cost Calculator gives you that figure directly. It's built on the same method Rohde has used in Europe for years, and it works from three pieces of information.

The first is your kiln model. Each Ecotop has a different mass of insulation, and heating that mass accounts for a large share of the energy any firing uses. The second is your firing type, from a Cone 017 decor firing for gold and luster up to a Cone 10 glaze. The third is how full the kiln is, which has a greater effect on cost per piece than most people expect. Add your electricity rate — it's printed on your monthly statement as a price per kilowatt-hour — and the calculator returns the cost of that single firing.

Why loading matters so much

This is the part that tends to be most useful in practice.

A kiln has to heat itself before it can heat anything else. The insulation, the elements, the shelves and the posts all climb to temperature regardless of how much work is inside, and on smaller kilns that fixed cost makes up the majority of the energy used. The ware itself is a comparatively small addition.

The practical result is that the cost of a firing changes only modestly with load, while the cost per finished piece changes considerably:

Kiln fill	Ware	Cost	Cost per pound
25%	13 lb	$3.72	$0.28
50%	26 lb	$4.06	$0.15
75%	40 lb	$4.40	$0.11
100%	53 lb	$4.74	$0.09

Ecotop 60 S, Cone 6 glaze, $0.17/kWh

Loading fully rather than a quarter full reduces the energy cost of each piece by roughly two thirds. It's a larger swing than anything the cone choice produces: moving from the lowest firing to the highest changes cost per pound by a little under double, while moving from a quarter-full kiln to a full one changes it by around three times. Temperature is set by the work. How you pack the kiln is entirely up to you.

Adjusting the load slider in the calculator shows the same effect across any model and any firing.

Ecotop Firing Cost Calculator

Choose your model, your firing type, and how full your kiln is. We'll estimate the electricity needed to power.

Kiln model

Firing type

How full is the kiln? 100%

Empty shelves still cost you — the kiln itself has to get hot.

Your electricity rate

$ per kWh

Check your utility bill. The U.S. average runs about $0.17.

Cost per firing

$13.00

76.5 kWh · 220 lb of ware

How we got there

Kiln weight	—
Kiln volume	—
Ware in the kiln	—
Heat capacity, total	—
Temperature rise	—
Energy	—

A sense of the range

An Ecotop 60 S, loaded to capacity for a Cone 6 glaze firing at $0.17 per kWh, uses about 27.9 kWh and costs roughly $4.74. That covers approximately fifty-three pounds of finished work. A larger Ecotop 250 S doing the same firing uses about 79.3 kWh at a cost near $13.47, for around two hundred and twenty pounds of ware.

Temperature matters, but less sharply than you might assume. On that same 60 S, a Cone 017 decor firing costs about $2.83, a Cone 06 bisque about $3.86, and a Cone 10 glaze about $4.99. The energy required rises in direct proportion to the temperature you're climbing to rather than exponentially, so the whole usable cone range sits inside a few dollars.

What the estimate covers

The calculator determines the energy required to raise your kiln and its contents to temperature, using the actual weights and volumes of each Ecotop model together with the thermal properties of the insulation.

There are elements it doesn't include: time held at peak temperature, heat lost through the walls during a long or slow climb, and any demand charges your utility applies separately from the per-kilowatt-hour rate. Your real consumption will therefore be somewhat higher than the figure shown. We've chosen to give you the underlying baseline rather than apply an estimated adjustment, so you know exactly what the number represents.

Using it for your own studio

Find your rate per kilowatt-hour on your most recent bill, then work through the firings you actually do — your standard bisque, your usual glaze, at the load levels you typically achieve. Over a month of firings, the totals give you a reasonable picture of what your kiln contributes to your electricity costs.

If you're comparing two Ecotop sizes, it's worth running both. Larger kilns cost more per firing but less per pound of finished work, and seeing those two figures side by side often clarifies the decision.

Blog posts

Clay Trap Installation: The 3 Questions We Get Most

A clay trap only works if it's plumbed right. And most installation questions we field come down to three things: where to put your drain, which part is which, and whether it'll fit under your sink...