Kiln Electricity Cost Calculator

Because a kiln doesn't draw its full rated wattage continuously for the whole firing -- its controller cycles the elements on and off to hold temperature and manage the ramp schedule, so the true average draw over a full firing runs lower than the nameplate figure. This calculator applies a 70% duty cycle to Kiln Wattage before multiplying by Firing Duration, which is a reasonable approximation for a typical bisque or glaze schedule but will run higher for an aggressive ramp-heavy schedule and lower for a slow, well-insulated kiln.

No. Peak Demand and Amperage both describe the instantaneous draw while the elements are on, which depends only on Kiln Wattage -- Firing Duration only affects how long that draw is sustained, which is what Energy Used and Cost Per Firing capture instead. A 6-hour and a 10-hour firing on the same kiln pull the exact same peak amps; the longer firing just accumulates more total kWh.

Most electric hobby and studio kilns in North America over about 3-4 kW are wired for 240V circuits, since a 120V circuit would require unreasonably high amperage for the same wattage and typically can't supply enough current for anything beyond a small test kiln. If your kiln is actually wired at 120V, double the Amperage figure shown here to check against your circuit's breaker rating.

It's a reference point, not a fixed monthly bill -- it's simply Cost Per Firing multiplied by 4, so you can scale it linearly for your own firing frequency (multiply Cost Per Firing by however many times you actually fire per month instead). It's most useful as a quick sanity check for studio budgeting when you don't yet know your exact firing schedule.