How Hot Does A Kiln Need To Be For Pottery?
By Linda · · 6 min read
A kiln needs to reach between 1,828°F and 2,345°F (998°C and 1,285°C) to fire pottery, depending on the clay you’re using. Bisque firing happens at the low end of that range, around 1,828–1,945°F (998–1,063°C), while glaze firing for stoneware and porcelain typically requires 2,232–2,345°F (1,222–1,285°C).
There’s no single “pottery temperature.” The right firing temperature depends on your clay body, your glaze, and whether you’re doing a first (bisque) or second (glaze) firing. Below I break down the exact temperatures for each clay type and firing stage.
Firing Temperatures by Clay Type
Every clay body has a maturation range, the temperature at which it becomes as dense and durable as it’s going to get. Fire below that range and the clay stays porous and weak. Fire above it and the clay can slump, bloat, or melt onto your kiln shelf.
| Clay Type | Cone Range | Temperature (°F) | Temperature (°C) |
|---|---|---|---|
| Earthenware (low-fire) | Cone 06–04 | 1,828–1,945°F | 998–1,063°C |
| Mid-range stoneware | Cone 5–6 | 2,167–2,232°F | 1,186–1,222°C |
| High-fire stoneware | Cone 8–10 | 2,280–2,345°F | 1,249–1,285°C |
| Porcelain | Cone 8–12 | 2,280–2,419°F | 1,249–1,326°C |
A few practical notes:
- Cone 6 (2,232°F / 1,222°C) is the sweet spot for most home potters. Mid-range stoneware vitrifies fully, glazes are plentiful, and you’re not pushing your electric kiln’s elements to their limit.
- Earthenware never fully vitrifies, even at the top of its range. That’s why terracotta pots are porous. It’s the nature of the clay, not a firing mistake.
- Always match your glaze to your clay’s cone. A cone 06 glaze fired to cone 6 will run right off the pot and weld it to your shelf.
What Do Cone Numbers Mean?
Potters measure firing with pyrometric cones rather than temperature alone, because cones measure heatwork, the combination of temperature and time. Two firings can hit the same peak temperature but produce different results if one climbed faster than the other.
The numbering trips up every beginner: cones with a leading zero (06, 04) are cooler than cones without (5, 6, 10). Cone 06 is roughly 1,828°F (998°C), while cone 6 is roughly 2,232°F (1,222°C) — a difference of about 400°F. Misreading “06” as “6” ruins more pots than almost anything else, so double-check your glaze labels.
Modern electric kilns with digital controllers handle this for you. You pick a cone number and the controller manages the climb. Manual kilns rely on physical cones that bend when the correct heatwork is reached.
How Hot Can a Kiln Get?
Most pottery kilns max out somewhere between 2,350°F and 2,450°F (1,288–1,343°C):
- Electric kilns: most hobby and studio models are rated to cone 6–10, roughly 2,232–2,345°F (1,222–1,285°C). Regularly firing a kiln at its maximum rated temperature wears out the elements faster.
- Gas kilns: commonly fired to cone 10 (2,345°F / 1,285°C) and capable of reduction atmospheres, which electric kilns can’t easily produce.
- Wood kilns: reach cone 10–12 over long firings that can last days, with ash deposits creating natural glaze effects.
- Raku kilns: only taken to about 1,800°F (982°C) before pieces are pulled out glowing hot.
For comparison, glass kilns typically top out around 1,700°F (927°C), well below pottery temperatures. That’s why a glass kiln generally can’t fire clay to maturity. And a home oven reaches only about 500°F (260°C), nowhere near enough. I cover why in can you fire pottery in an oven.
Bisque Firing vs. Glaze Firing Temperatures
Most pottery is fired twice, and the two firings target different temperatures.
The bisque firing comes first, usually to cone 06–04 (1,828–1,945°F / 998–1,063°C). This burns out organic material and chemically bound water, leaving the pot hard but still porous enough to absorb glaze. It’s deliberately fired low because bisque ware needs to stay absorbent.
The glaze firing goes to the clay’s full maturation temperature: cone 6 (2,232°F / 1,222°C) for mid-range stoneware, cone 10 (2,345°F / 1,285°C) for high-fire work. This melts the glaze into glass and vitrifies the clay body.
A typical firing takes 8–12 hours to reach temperature, then another 12–24 hours to cool. Never open the kiln above about 125°F (52°C). The thermal shock can crack your pots. I break down full schedules in how long does pottery take to fire.
What Happens If You Fire Too Low or Too High?
Underfiring leaves clay porous and fragile. Underfired functional ware will weep water, harbor bacteria, and chip easily. Underfired glaze looks dry, rough, or milky instead of glassy. It hasn’t melted, plain and simple.
Overfiring is worse. Glazes run off the pot and fuse to the kiln shelf, low-fire clay can bloat or slump, and in extreme cases the clay itself melts into a puddle that destroys the shelf. If you ever fire borrowed or unknown clay, test a small piece first.
Heating too fast causes its own problems. Trapped moisture turns to steam, and pieces can blow apart in the first hour of firing. I cover prevention in why does pottery explode in the kiln. The slow climb through the first 1,000°F matters more than most beginners realize.
Kiln Safety at Pottery Temperatures
At 2,200°F and up, the kiln’s exterior surfaces can exceed 400°F (204°C), so safety isn’t optional:
- Keep at least 12–18 inches of clearance between the kiln and any wall, and never fire near anything flammable.
- Vent the kiln. Firing releases carbon monoxide, sulfur compounds, and fumes from glazes, so a downdraft vent or strong room ventilation is essential.
- Wear kiln gloves and infrared-rated safety glasses when peering through the peephole at high temperatures.
- Never leave a manual kiln unattended near the end of a firing, and keep children and pets away during the entire cycle.
- Install the kiln on a non-combustible surface (concrete, kiln stand) and have an electrician confirm your circuit can handle the load.
If you don’t own a kiln yet, you have options: many studios rent kiln space (see where can I fire my pottery), and techniques like pit firing work without a kiln at all, though they only reach earthenware temperatures.
FAQ
How hot does a kiln get?
Most pottery kilns fire between 1,828°F and 2,345°F (998–1,285°C) in normal use. The maximum for typical electric kilns is around 2,350–2,400°F (1,288–1,316°C), while gas and wood kilns can sustain cone 10–12 temperatures.
How hot is a kiln for clay?
It depends on the clay: earthenware fires at 1,828–1,945°F (998–1,063°C), mid-range stoneware at 2,167–2,232°F (1,186–1,222°C), high-fire stoneware at up to 2,345°F (1,285°C), and porcelain as high as cone 12 (about 2,419°F / 1,326°C). Check the cone rating printed on your clay’s bag and fire within that range.
How hot can a kiln get at maximum?
Hobby electric kilns generally max out at cone 10, about 2,345–2,400°F (1,285–1,316°C). Industrial and specialty kilns can exceed 3,000°F (1,649°C), but no pottery clay needs temperatures that high.
What temperature is a bisque firing?
Bisque firing is typically done at cone 06–04, which is 1,828–1,945°F (998–1,063°C). This hardens the clay while leaving it porous enough to accept glaze.
Can I fire pottery at a lower temperature than recommended?
You can, but the clay won’t vitrify and the glaze won’t mature. Underfired pots are weak and porous, and they’re not safe for food or liquids. Always fire to the cone your clay and glaze are rated for.
How hot does the outside of a kiln get?
The exterior of an electric kiln can reach 250–500°F (121–260°C) during a glaze firing, depending on the model and insulation. That’s hot enough to burn skin instantly, so keep clearance around the kiln and keep kids and pets out of the room.