Build a precise kiln firing schedule by cone
Choose your Orton cone, bisque or glaze, and a speed. Get an exact ramp and hold schedule, with the heat-work read straight from the Orton cone chart, and a print-ready PDF to tape to the kiln.
Built on published charts, not guesswork
Orton calibrates its pyrometric cones to a heating rate of 108 F (60 C) per hour over the last 180 F of a firing, and publishes the exact temperature each cone bends at. Cone 6, for example, is rated at 2232 F (1222 C) at that rate. This tool reads those values and pairs them with the standard slow, medium, and fast cone-fire programs from Bartlett, Skutt, and L&L controllers.
Cone 6 bends at about 2232 F (1222 C) when fired at the standard 108 F per hour. Fire faster, at 270 F per hour, and the same cone needs about 2269 F (1243 C) to bend. That 37-degree gap is heat-work in action.
Source: Edward Orton Jr. Ceramic Foundation, pyrometric cone temperature chart (ortonceramic.com).Understand what every segment is doing
How kiln firing schedules work
A clear guide to kiln firing schedules: what a ramp rate and a hold are, why cones measure heat-work, and how the final ramp sets the peak temperature.
Read the guide 02Orton cone temperature chart
Orton pyrometric cone chart in Fahrenheit and Celsius, cone 022 to 10, at standard and fast heating rates. A cone is heat-work, not a fixed temperature.
Read the guide 03Bisque vs glaze firing
Bisque vs glaze firing, side by side: the cones each uses, why bisque ramps slower for organics, and how glaze schedules add a hold to smooth the melt.
Read the guideFrequently asked questions
How accurate is the schedule this tool builds?
The peak temperatures come straight from the Orton pyrometric cone chart, and the ramp and hold steps follow the standard Bartlett, Skutt, and L&L factory cone-fire programs that most studio kilns ship with. It is solid guidance, but every kiln fires a little differently, so fire a witness cone and adjust the final hold if it reads under or over.
Does the final ramp rate really change the temperature?
Yes. A cone measures heat-work, which is time plus temperature, not a single number. Fire slower over the last stretch and the cone bends at a lower temperature; fire faster and it bends higher. The builder reads the peak from the Orton column closest to your final ramp, so the heat-work stays right.
What is candling, and why does the schedule start so slow?
Candling means holding the kiln low, near 200 F (95 C), so any water left in the clay turns to steam and leaves gently. Skip it on damp or thick ware and trapped steam can crack or even burst a piece. The bisque schedules start slow for the same reason, then ease through quartz inversion near 1063 F (573 C).
Can I use this with a manual or kiln-sitter kiln?
The schedule assumes a programmable controller that takes ramp rates and holds. With a manual kiln you cannot set exact rates, but the segment targets and the witness-cone advice still help you judge low, medium, and high settings and when to shut off.
Is it really free, with no signup?
Yes. Build as many schedules as you like and download the PDF, with no account and nothing to install. The whole tool runs in your browser.