How much electricity does a kiln use?

You have your first kiln in sight, or you already own one and wonder after every firing what it does to your electricity bill. The question “How much electricity does a kiln use?” is one of the most common when it comes to firing at home or in your own studio. And it is a fair one: a kiln is not an electric kettle. But it is not a power hog to be afraid of either – if you know what matters.

We at Formwerk Berlin answer this question regularly – from customers who are just buying their first kiln to experienced potters who want to optimize their operation. 

Connected load vs. consumption: the most important difference

First, a distinction that confuses many people: the connected load (given in kilowatts, kW) is not the same as the actual electricity consumption (given in kilowatt hours, kWh). A kiln with a 7 kW connected load does not use 7 kWh per hour – because it does not heat at full power all the time.

Like an oven that switches on now and then to hold the temperature, a kiln regulates its heating output throughout the entire firing schedule. During the heat-up phase it often runs at 80–100 % power; during the hold and the controlled cooling, considerably less.

The electricity meter measures the kilowatt hours (kWh) used – the product of power and time.

As a rule of thumb, the real energy consumption of a firing is about 30–70 % of the theoretical maximum power times the firing time. The exact value depends heavily on the target temperature: for a bisque firing to 900–1,000 °C, the load factor is often 35–45 %, because the kiln can hold the temperature with comparatively little power. For a high-fire to 1,260 °C+ the picture is different – shortly before reaching the final temperature the kiln runs almost at full load, and realistically you end up closer to 60–70 %.

This has a direct effect on costs: a high-fire is noticeably more expensive per firing than a low-fire – not only because of the longer firing time, but also because of the higher load in the final phase.

Typical values: small kilns on a household outlet

Small kilns up to about 80 liters often run on a normal 230V Schuko outlet – this is the entry point for many hobby potters who want to fire at home. These kilns typically have a connected load of 2.0 to 3.6 kW. A typical bisque firing (up to about 1,000 °C) takes around 5 to 6 hours to heat up. On top of that comes the cooling time until you can open the kiln.

In concrete terms: a small 230V kiln with 2.5 kW connected load realistically uses about 8–12 kWh per bisque firing. That is above the rule of thumb above, because a kiln with so little power has to heat almost continuously while ramping up. At the average electricity price of 37.3 cents per kWh (BDEW, new customer tariffs, as of October 2026), a bisque firing costs roughly 3 to 4.50 euros. That is inexpensive – and easy to manage in most households without tripping the fuse, provided the kiln runs on its own circuit.

Important: check whether the outlet and the wiring are rated for continuous operation. A kiln running for 8 hours on an ordinary power strip is not a good idea. A direct connection to its own fused outlet – ideally installed by an electrician – is the right solution.

A concrete example: The Kittec CB 80 PLUS kiln is a top-loading kiln with 79 liters of usable volume and a connected load of 3.6 kW. It runs on 230V and reaches 1,200 °C (± 30 °C) according to Kittec. That makes it one of the largest kilns you can still run without three-phase power – and a real classic for home use. With its 3.6 kW connected load and a realistic utilization factor of about 45%, a typical bisque firing (about 6 hours of heating time) uses roughly 10 kWh. At 0.37 euros per kWh, that comes to electricity costs of around 3.70 euros per firing. For glaze firings up to 1,200 °C, expect significantly more energy and a longer firing time, because at this temperature the kiln works at its power limit.

You can find the entire Kittec CB Classic line in our shop in various sizes from 20 to 95 L – with and without three-phase connection.

Mid-sized and large kilns: three-phase power from 400 V

As soon as you start thinking about 100 liters and more, you can't avoid a 400V three-phase connection (CEE 16A or CEE 32A). If you regularly fire high, you are also often better served with more power, even though some smaller 230V kilns reach up to 1,320 °C. These kilns typically have connected loads of 6 to 14 kW.

Let's take a popular mid-range kiln with 138 liters and 9.6 kW connected load as an example. A stoneware firing to 1,280 °C, including cooling, often takes 10–14 hours, but the kiln only heats for part of that time. Realistically, such a firing uses about 30–45 kWh – depending on insulation, kiln load and firing schedule. At 0.37 euros/kWh that would be 11 to 17 euros per firing. For context: for its Top 100 top-loading kiln with 100 liters and 7 kW, Nabertherm states that bisque firing (950 °C) and glaze firing (1,250 °C) together need 56.7 kWh. Extrapolated to the larger 138 liter kiln, the glaze firing alone lands in the range mentioned.

For a small ceramics studio that does two firings per week, this results in operating costs of about 95–145 euros per month – a manageable item that is easy to budget.

A concrete example: A popular model from our range is the Pyrotec Profitherm PY 138 HS, which has exactly 138 liters of firing chamber and a connected load of 9.6 kW at 400V – it is connected via a CEE 32A plug. As with any kiln, its actual consumption is far below the theoretical maximum of 9.6 kW times firing duration. For a stoneware firing you can roughly count on 30 to 45 kWh as above, which at 0.37 euros/kWh means about 11 to 17 euros per firing. A firing at a lower temperature, such as a bisque firing, costs correspondingly less. If you do two firings per week, that comes to operating costs of around 95–145 euros per month – an easy figure to plan around for a small studio or an active hobby studio.

So what does it cost to run a pottery kiln?

This question can be approximated with a simple formula:

Cost per firing = connected load (kW) × firing time (h) × load factor × electricity price (€/kWh)

Firing time here means the time the kiln is heating, so ramp-up plus hold, without the cooling phase. Depending on the firing, you can assume a load factor of 0.35 to 0.7, closer to the lower end for a bisque firing and closer to the upper end for a high firing. This is the share of time during which the heating elements are actually on. The calculations below use 0.37 euros per kWh:

A good reference point for the most important kiln sizes:

• Small 230V kiln (~2.5 kW, ~50 L, bisque up to 1,000 °C): approx. €3–4.50 per firing
• Mid-size kiln with three-phase power (~7 kW, ~100 L, stoneware up to 1,280 °C): approx. €10–15 per firing
• Large studio kiln (~12 kW, ~200 L, high fire up to 1,320 °C): approx. €20–28 per firing

These figures vary depending on your electricity tariff, kiln insulation and how fully you load your kiln. A well-filled kiln is more efficient than a half-empty one – the ware stores heat and helps keep the temperature even.

What affects consumption?

Besides kiln size and target temperature, several factors have a significant effect on the energy consumption of a firing:

• Insulation: High-quality kilns use multilayer insulation – for example insulating firebrick in the firing chamber with backup insulation made of microporous insulating material. Well-insulated kilns lose less heat to the outside, need less energy to heat up and hold the temperature more steadily. This is one of the most important quality differences between inexpensive and high-quality kilns – and it shows up directly on your electricity bill.
  
  
• Loading: A fully loaded kiln uses the energy invested more efficiently than an empty one. The ware absorbs heat and releases it slowly again – this stabilizes the firing schedule and noticeably lowers the total consumption per fired piece.
  
  
• Firing schedule: Fast firings usually need less electricity, because the kiln loses heat to the outside for a shorter time. But heating up too fast can lead to uneven results or cracks and puts more strain on the heating elements. A suitable, well-programmed firing schedule is therefore more important than the last saved kilowatt hour. A good controller like the Bentrup TC66 helps you program and save such schedules precisely.
  
  
• Age of the heating elements: Older heating elements have a higher electrical resistance. Since power decreases as resistance rises (P = U²/R), the kiln takes longer to reach its target temperature. And the longer a firing lasts, the more heat the kiln loses to the outside through its walls – which drives up total consumption. The result is the same as with an “inefficient” appliance, but the mechanism is different: not less heat per watt, but more time – and therefore more wall losses. If your kiln takes noticeably longer than it used to or barely reaches certain temperatures anymore, it is worth checking the condition of the elements. How to spot wear is explained in Replacing heating elements. Spare parts for our models – including heating elements and thermocouples – are available in our accessories section.
  
  
• Energy saving package (ESP): For the Kittec CB series, an energy saving package with additional premium insulation is optionally available, and the NewGen ESP variant also comes with lighter bricks made of foam ceramic. In a Kittec test with a CB 95 S, NewGen ESP saved 8.5 kWh compared to the standard version in a firing to 1,250 °C according to the manufacturer, which at 0.37 euros per kWh is about 3.10 euros per firing. How quickly the extra cost pays off depends on how often you fire.

Firing at home: what do you need to watch out for electrically?

If you want to run a 230 V kiln at home, the electrical infrastructure is your first checkpoint. Modern households usually have circuits protected with 16 A – that corresponds to a maximum power of about 3,680 watts. A small kiln with 2–3 kW falls within this range.

Even so: never run your kiln on a power strip, and ideally use its own circuit without other large consumers. Continuous operation over several hours puts a strain on the outlet and wiring – an electrician can quickly check whether your connection is suitable. What you need to keep in mind in a rental apartment is covered in Kiln in a rental apartment: is it allowed?

For larger kilns from about 100 liters, a three-phase connection (400 V, CEE) is usually required. The installation is a one-time effort. What it costs depends mainly on the distance between the fuse box and the place where the kiln will stand, so get a quote from a qualified electrician. In the long run it pays off, because it gives you more flexibility when choosing a kiln.

A CEE connection (400 V) is usually a basic requirement for larger kilns.

Tip: use night firings and time-of-use rates

If you have a modern programmable controller, you can set your kiln to start at a certain time – and, for example, let it run at night when the electricity rate is cheaper. Some providers offer night-rate or dynamic tariffs where electricity is considerably cheaper at certain times. For dynamic tariffs, however, you need a smart meter. For a 30–40 kWh firing, this makes a difference of several euros – and over the year it adds up.

Conclusion: no reason to worry – but calculate consciously

A kiln is not a power monster that blows up your annual bill. With the right numbers in mind, running it can be planned and budgeted well – whether you fire once or twice a month for your own use or run a small workshop.

The key point: don't buy the smallest kiln to save electricity – buy the right kiln for your pieces. A well-filled, high-quality kiln with good insulation is more efficient and cheaper in the long run than an undersized one that you have to fire more often. In our kiln range at Formwerk Berlin you will find models from Kittec, Nabertherm and Pyrotec – from small 230V entry-level kilns to professional studio kilns for high firing. We are happy to work out which kiln suits your space, your power connection and your work in our free kiln consultation. Our kiln comparison also gives you an overview of the most popular models, and Firing ceramics: basics, temperatures and technique explains what happens during the firing itself.

Note: The values given are for orientation and may vary depending on kiln model, loading, firing schedule and electricity rate. For the electrical installation and operation of a kiln, we recommend having it checked by a qualified electrician.

PS: On all kilns you get 5% off with the code WELCOME5. Just enter it at checkout – and your next firing is a little cheaper.

Happy firing, your Formwerk Team