Kiln Firing Cost Calculator

How it works

kWh = rated kW × (ramp hours + hold hours) × duty cycle; electricity cost = kWh × tariff; element wear per firing = element set cost ÷ element life; cost per piece = total ÷ pieces

A kiln’s nameplate kilowatts are its maximum draw; the controller switches the elements on and off to follow the programme, so the average power over a firing is the rating times a duty cycle — around 40–50% for a slow bisque, 60–75% for a cone 6 glaze firing where the kiln fights heat loss near peak, and higher still for cone 10 or an old, tired element set. Multiplying by the hours to temperature (cooling costs nothing) gives kilowatt-hours and, with the tariff, the electricity bill for the load. Elements are a real consumable — a set lasts roughly 100–150 firings at mid-range temperatures, fewer at cone 10 — so spreading their cost over firings gives a truer per-piece figure. Firing full loads is the biggest lever; a half-empty kiln costs almost the same.

Worked example

A 7.2 kW kiln fired 9 hours plus a 15-minute hold at 65% duty uses 43.3 kWh — $6.93 at 16¢/kWh, plus $3.33 of element wear ($400 set over 120 firings): about $10.26 per firing, 34¢ per piece with 30 pieces, and $62 a month for six firings.

Frequently asked questions