How hot does a kiln get? An electric pottery kiln for home use typically reaches about 1,830°F to 2,350°F (999°C to 1,288°C), depending on the cone you program and the kiln's rating. Low-fire work stops near the bottom of that range, while stoneware and porcelain fired to cone 10 need the top of it. The kiln itself has a ceiling too: most hobby models are built for either cone 6 or cone 10.
This guide is research-based. We compared kiln maker spec pages and manuals with Orton's published cone chart; we did not fire a kiln for this article. Sources are listed at the end.
Kiln temperature by firing type
Potters talk in cones rather than degrees, because a cone measures the combined effect of temperature and time (called heatwork). The table below turns the common cones into temperatures using Orton's chart for self-supporting cones at a final heating rate of 108°F per hour, which is close to how many electric kilns finish a firing.
| Firing | Typical cone | Temperature (108°F/hr finish) | What it is for |
|---|---|---|---|
| Lusters, decals, china paint | 022 to 018 | 1,094°F to 1,319°F (590°C to 715°C) | Overglaze decoration on already glazed ware |
| Low-fire glaze | 06 to 05 | 1,828°F to 1,888°F (998°C to 1,031°C) | Earthenware and bright commercial glazes |
| Bisque firing | 06 to 04 | 1,828°F to 1,945°F (998°C to 1,063°C) | First firing of dry greenware |
| Mid-fire glaze | 5 to 6 | 2,167°F to 2,232°F (1,186°C to 1,222°C) | Most home stoneware and porcelain |
| High-fire glaze | 10 | 2,345°F (1,285°C) | Traditional stoneware and porcelain |
The full list from cone 022 to cone 10, in both Fahrenheit and Celsius and at two heating rates, is on our pottery cone chart. If you are new to cones, how pyrometric cones work explains what the numbers mean.
How hot do kilns get at their maximum?
Every kiln has a maximum temperature printed on its serial plate, and Skutt's operating manual tells owners never to exceed it. Here is what makers state for several kilns often bought for home studios.
| Kiln | Power | Maker's maximum | Practical use |
|---|---|---|---|
| Skutt KM-1027 | 240V, 48A (single phase) | Cone 10, 2,350°F (1,288°C) | Cone 6 everyday, cone 10 possible |
| Skutt KM-818 | 240V, 26.7A | Cone 10, 2,350°F (1,288°C) | Cone 6 everyday, cone 10 possible |
| Skutt KM-614-3 | 115V, 20A | Cone 6, 2,250°F (1,232°C) | Low fire and cone 5 to 6 |
| Skutt Firebox 8x6 LT | 115V, 15A | Cone 6, 2,250°F (1,232°C) | Small pieces and tests |
| Paragon Caldera | 120V, 14A | 2,350°F (1,288°C) | Test tiles and small work |
| Paragon Xpress E-10A | 120V, 15A | 2,000°F (1,093°C) | Low fire, glass and metal clay only |
Two things stand out. First, a 120V kiln can reach cone 6, but most of the small ones stop there. Second, a kiln rated to 2,350°F reaches cone 10 with little margin, because cone 10 is about 2,345°F at a 108°F per hour finish. One dealer listing for the KM-818 says it should only fire to cone 10 occasionally, and many owners fire cone 6 for routine work to save element life. For a full comparison of models, see the best electric kilns.
Skutt's current KM-818 page lists 26.7A and 6,400 W at 240V. A dealer listing we checked during our September research showed 27.8A and 6,660 W. Use the figures on your kiln's serial plate and Skutt's own page when you plan the circuit.
What limits how hot a kiln can get
Elements and wattage
Electric kilns heat with coiled wire elements. The more watts the elements deliver for the size of the chamber, the easier it is to climb at the end of a firing. Voltage matters: Skutt lists the KM-818 at 6,400 W on 240V but 5,550 W on 208V, which is why kilns are wired for a specific supply. As elements age they lose power, so firings slow down near the top and may stall short of the target. Our guide to kiln elements covers the warning signs.
Higher wattage also means a bigger electric draw while the kiln is on; how that adds up per firing, and whether kilns use a lot of electricity, is worked through in our guide to how much a kiln costs.
Brick and lid
Thicker insulating brick holds heat better. Many cone 10 home kilns use 3 in brick, and some economy models use 2.5 in. A worn lid seal or a cracked brick lets heat escape and makes the top section run cooler.
The controller and thermocouple
The controller reads temperature from a thermocouple poking into the chamber. If the thermocouple drifts, the kiln may report 2,232°F while the ware sees something different. That is the main reason potters still put witness cones on a shelf. Our guide to kiln controllers explains how the controller and thermocouple work together.
Why heating rate changes the temperature you need
Cones respond to heatwork, not just peak temperature. A slow finish gives the clay and glaze more time to react, so the same cone bends at a lower temperature. Orton's chart shows this clearly for self-supporting cones:
- Cone 06: 1,798°F at 27°F/hr, 1,828°F at 108°F/hr, 1,855°F at 270°F/hr
- Cone 04: 1,915°F, 1,945°F and 1,971°F
- Cone 6: 2,165°F, 2,232°F and 2,269°F
- Cone 10: 2,284°F, 2,345°F and 2,381°F
Orton bases those columns on the heating rate during the last 180°F (100°C) of the firing. So "cone 6" can mean anything from roughly 2,165°F to 2,269°F on the thermocouple, and a long hold at the top adds even more heatwork. This is why a kiln that hits its programmed number can still under-fire or over-fire your glaze.
How long does a kiln take to heat up?
Most pottery firings take several hours to climb and as long again, or longer, to cool. Skutt's KilnMaster manual gives a worked example for cone 04: about 12 hours on the slow speed, 7.5 hours on medium and 4 hours on fast. Skutt recommends slow for large or thick-walled pieces and says fast is only for items such as lusters and decals.
Glaze firings to cone 6 follow a similar pattern, and the exact time depends on the program, the load and the kiln's power. A heavily packed kiln with thick shelves takes longer than a half-empty one. A preheat (candling) step, used to drive off remaining water, adds hours at the start. Our guide to how long it takes to fire pottery breaks down typical schedules.
Do not open the lid to "check" during cooling. Sudden cold air can crack ware and shelves. Wait until the controller reads close to room temperature, following the cooling advice in your kiln manual.
How long does a kiln take to cool down?
Cooling usually takes as long as heating, or longer. Laguna's cone 5/6 glaze firing guide says cooling takes about the same time as the heating phase, and Skutt's KilnMaster manual simply tells owners to let the kiln cool naturally. Neither maker publishes a fixed number of hours, because a big, fully loaded brick kiln holds far more heat than a small test kiln with two shelves.
What Skutt does publish is the finish line. Its manual says not to unplug extra peepholes or prop the lid until the ware is cool enough for barehanded unloading, about 130°F (54°C), and recommends against unloading above 125°F. So when the display passes 1,000°F (538°C) on the way down, you are still a long way from that point: the kiln has to lose almost 900°F more, and the rate of cooling slows as the kiln nears room temperature. Plan a bisque or glaze firing as a two-day job.
How hot does the outside of a kiln get?
Hot enough to burn you. Skutt's manual warns that the stainless steel jacket and some fixtures around the kiln will get hot enough to burn skin while the kiln is firing. Makers do not publish a single exterior temperature, because it varies with the model, brick thickness and how far into the firing you are. One potter on the Ceramic Arts Network forum reported about 350°F (177°C) on the lid of a top loader at cone 5, which is a single owner's reading rather than a spec.
That heat is why clearance matters. Skutt's manual asks for a minimum of 18 in (46 cm) between the kiln and walls, other kilns, shelving and anything else nearby. Check your own kiln's manual, local code and the guidance in our kiln placement and clearance guide.
Keep children, pets, paper, curtains, solvents and stored clay boxes away from a firing kiln. Never lean on the lid or rest tools on the jacket. Fumes from clay and glaze burnout need to leave the room, so follow the maker's ventilation advice (a kiln vent is the usual answer). Have a licensed electrician install or check the kiln circuit; do not wire it yourself.
Clay and kiln temperature: matching the two
Your clay's firing range sets how hot the kiln needs to get, not the other way around. Some examples from clay maker data:
- AMACO No. 25 White Art Clay, a low-fire body, lists a range of cone 04 to cone 3.
- Laguna B-Mix 5 is a cone 5 body, and Laguna's speckled version warns against over-firing past cone 5.
- AMACO No. 46 Buff Stoneware fires from cone 5 to 10, with best results at cone 5.
Firing a low-fire clay to stoneware temperatures can slump or melt it onto the shelf, so always check the cone printed on the bag before you program the kiln.
Common mistakes with kiln temperature
- Trusting the display alone. A drifting thermocouple or worn elements can leave you a cone short. Witness cones show what the ware received.
- Buying a cone 6 kiln for cone 10 clay. If you want high fire, choose a kiln rated to 2,350°F and wired for 240V.
- Firing every load at the kiln's maximum. Routine firings at the top of the rating wear elements faster.
- Comparing kitchen ovens with kilns. A home oven tops out far below even cone 022, so it cannot fire clay; see pottery oven vs kiln.
- Adding long holds without adjusting the cone. A hold adds heatwork, so a cone 6 program with a long hold can behave like a hotter firing.
What you need
If you are still choosing a kiln, start with what your clay needs: cone 6 covers most home stoneware, and a 240V kiln rated to cone 10 gives room to grow. Our best kilns for home pottery guide compares sizes, power needs and maximum temperatures for the kilns home potters buy most.
Sources: Orton Ceramic Foundation, Temperature Equivalents for Orton Pyrometric Cones (self-supporting cone columns) and Orton pyrometric cones pages; Skutt product pages for the KM-818 and KM-1027; Skutt KilnMaster operating manual (firing speeds, preheat, clearance, exterior heat warning); Skutt, Paragon and dealer spec pages for the KM-614-3, Firebox 8x6 LT, Caldera and Xpress E-10A (from our September 2026 product research); New Mexico Clay KM-818 listing; AMACO clay pages for No. 25 and No. 46; Laguna B-Mix 5 pages; Laguna Clay cone 5/6 glaze firing guide (PDF, cooling time); Skutt KM operating manual (installation location, floor, unloading temperature); Ceramic Arts Network community forum thread on kiln exterior temperature. Specs checked October 2026.