Kiln Firing Cost Calculator

In short The number people reach for first is the kiln’s nameplate power times the hours, and it is wrong by a wide margin. A 10 kW kiln firing for nine hours does not use 90 kWh, because the elements are not on for nine hours — the controller cycles them to hold the ramp, and they are off for much of the climb and most of any hold. A realistic duty factor of about 60% puts the same firing at 54 kWh, which at 0.28 a unit is 15.12 rather than 25.20. THE DUTY FACTOR IS THE ONLY ESTIMATE ON THIS PAGE and everything else is arithmetic. Somewhere between 50% and 70% is usual for a full firing: lower for a long slow bisque where the kiln spends hours barely working, higher for a fast climb to cone 10 where the elements are on almost continuously near the top. If your meter can show you a single firing — a smart meter, a plug-in monitor on a smaller kiln, or simply reading the dial before and after — that measurement beats every estimate here, and it is the one thing that makes this page accurate for your kiln rather than accurate in general. COST PER POT IS THE FIGURE THAT ACTUALLY DECIDES ANYTHING. The same firing across 24 pieces is 63p each; across 12 it is double. That is the real argument for waiting until you have a full load rather than firing a half-empty kiln twice, and it is why studio hire is usually priced by the shelf rather than by the hour. Remember also that most pots go through two firings, bisque and glaze, so the electricity in a finished piece is the sum of both. Three things this does not include, and they are not small. Elements wear out and a replacement set is a real cost spread across firings. Kiln shelves and wash have a life. And nothing here counts the clay, the glaze or your time — this is the electricity line and nothing else.