The Skutt KM818 is the full-size kiln most home studios end up with: an 18 inch opening, 18 inches deep, 2.6 cubic feet, cone 10 on both 240V and 208V, and a 40A circuit. It holds about 12 tea bowls 6 inches wide by Skutt's count, which suits a potter who fires every week or two.
This review is research-based. We compared Skutt's KM-818 product page, its 2023 ceramic kiln catalog, its current contractor installation sheet, an older Skutt electrical spec sheet (revised 1999), the KilnMaster operating manual and dealer listings from Clay-King, The Ceramic Shop and Sheffield Pottery, checked October 2026. We did not fire this kiln. For the full Skutt range, see our Skutt kilns review.
Verdict
For a home potter who can add a 240V, 40A circuit, the KM-818 is an easy recommendation. It reaches cone 10, uses Skutt's KilnMaster controller with cone-fire presets, comes apart in sections for moving, and is stocked by dealers across the US. Skutt's catalog says its cone 10 power "makes it perfect for porcelain".
Choose the KM-818-3 if you want 3 inch brick and accept a slightly smaller chamber. Choose the KM-818-30A-3 only if a 30A circuit is all you can get, because it is rated to cone 8. Skip the 818 family entirely if you only have 120V or already fill a kiln twice a week.
Skutt KM-818 specs by version
| Version | Amps and watts | Breaker and copper wire | Receptacle (NEMA) | Max cone | Interior | Brick and shipping weight |
|---|---|---|---|---|---|---|
| KM-818, 240V 1-phase | 26.7A, 6,400 W | 40A, #8 | 6-50 | Cone 10, 2,350°F (1,288°C) | 18 x 18 in opening, 18 in deep, 2.6 cu ft | 2.5 in; 145 lb |
| KM-818, 208V 1-phase | 26.7A, 5,550 W | 40A, #8 | 6-50 | Cone 10, 2,350°F | Same | 2.5 in; 145 lb |
| KM-818-3, 240V or 208V | 26.7A, 6,400 or 5,550 W | 40A, #8 | 6-50 | Cone 10 | 16.5 in opening, 18 in deep, 2.3 cu ft | 3 in; 160 lb |
| KM-818-30A-3, 240V | 21.7A, 5,200 W | 30A, #10 | 6-30 | Cone 8, 2,300°F (1,260°C) | 16.5 in opening, 18 in deep, 2.3 cu ft | 3 in; 160 lb |
| KM-818-30A-3, 208V | 24.0A, 4,990 W | 30A, #10 | 6-30 | Cone 8, 2,300°F | Same | 3 in; 160 lb |
- Outside width: 23 in for Skutt's 8-sided kilns (2023 catalog); exterior height and dry weight not published by the maker
- Controller: KilnMaster 12-key, 12 programs of up to 32 segments; KMT touchscreen version sold
- Included: stand with feet, extra thermocouple, peep plugs, instructional video
- Price band: typically $2,300 to $3,000 at US dealers in October 2026 for the standard KM-818; check the live price
Source notes, checked October 2026: Skutt's product page, 2023 catalog and 1999 spec sheet give 26.7A and 6,400 W at 240V. Skutt's current contractor installation sheet lists 27.8A and 6,660 W, which is where New Mexico Clay's figure comes from. Breaker (40A), wire (#8) and receptacle (6-50) agree everywhere, so our earlier pages stand. Skutt's product page gives an 18 x 18 inch opening while the catalog prints 17.5 inches. For the 30A model, the catalog, the 1999 sheet and Sheffield Pottery list a 6-30 receptacle while the installation sheet says 6-50, and Sheffield's spec table says cone 10 while its own text and Skutt's catalog say cone 8. Skutt's product page leaves the 30A row blank. Read the nameplate on the kiln you receive.
These are Skutt's stated figures. Skutt's installation sheet says most buyers need an electrician to install the right receptacle and circuit, and that its wire and breaker sizes follow the National Electrical Code. Have a licensed electrician check or install the circuit. Skutt adds that for runs over 50 feet the wire should be two sizes heavier. Do not wire a kiln circuit yourself.
KM-818, KM-818-3 or KM-818-30A-3: which to choose
All three share the 18 inch depth, the controller and the sectional build. The differences are brick and power.
- KM-818 (2.5 inch brick): the largest chamber in the family at 2.6 cubic feet and the lightest at 145 lb shipping. The default choice on a 40A circuit.
- KM-818-3 (3 inch brick): same 26.7A draw and cone 10, but the thicker wall cuts the opening to 16.5 inches and the volume to 2.3 cubic feet. Better heat retention; slightly less room.
- KM-818-30A-3: made for a 30A breaker and #10 wire. Lower wattage means a cone 8 rating, and Skutt's catalog says it is sold with 3 inch brick only.
The 30A model makes sense where a panel cannot spare 40A, or where an existing 30A dryer-style circuit is close to the kiln spot. It suits potters whose clay and glazes are cone 5 to 6. If you ever want cone 10, pay for the 40A circuit instead.
The KM-818 on 208V
Unlike the KM-1027, the standard KM-818 keeps its cone 10 rating on 208V single-phase. It draws the same 26.7A but makes 5,550 W instead of 6,400 W, so firings near the top take longer. Skutt warns that a 208V kiln must never be fired on 240V without first fitting a full set of 240V elements, and that 240V kilns should not be used on 208V, so order the voltage your building actually has. Low voltage can also make KilnMaster kilns show an error message.
What fits inside: real loading capacity
Skutt counts about 12 tea bowls 6 inches wide and 3 inches tall per load in the KM-818. That figure assumes a full kiln of identical small bowls; mixed loads of mugs, bowls and a vase usually come out lower.
The furniture kit shapes the load. Skutt's catalog lists two 5/8 inch full shelves, three 5/8 inch half shelves, 18 posts (three each from 1 to 6 inches) and an 8 oz bag of kiln wash for the 818. The Ceramic Shop lists the same counts with 15.5 inch shelves. In 18 inches of depth that gives three or four levels of mugs, or one level of tall pieces with a half shelf of small work beside them. Measure your tallest piece and add shelf thickness and a gap before buying the kiln. Our kiln shelves and furniture guide explains shelf materials and post sizes.
A 3 inch brick KM-818-3 has a smaller inside, so order the kit made for that model.
Cone 10 or cone 6 as your everyday firing
Skutt rates the KM-818 to cone 10 and markets it for porcelain. New Mexico Clay's listing describes cone 10 as occasional use. Both can be true: the kiln reaches cone 10, but firing at a kiln's top rating every time wears elements faster than firing below it. Skutt's manual says its kilns are designed to fire from cone 022 to cone 10.
Most home potters fire cone 04 bisque and cone 5 to 6 glazes in a KM-818 and keep cone 10 for special loads. Our pottery cone chart shows the temperatures.
Space, floor and setup
Skutt calls for at least 18 inches between the kiln and walls, other kilns and shelving. With a 23 inch outside width, plan on a clear square of floor about 59 inches (just under 5 feet) across, plus a walkway. Skutt's manual asks for a bare cement floor or 2 inches of masonry under the kiln reaching 12 inches past it, no sprinkler head within 10 feet above, and a room at or below 105°F and above freezing.
The KM-818 ships at about 145 lb on a 32 inch freight pallet and should arrive assembled. The sectional design lets you lift sections off to carry it down stairs. Unlike Skutt's 10 and 12-sided kilns, the 818 does not list a lid lifter as standard.
What a firing costs, worked from Skutt's watts
At 6,400 W, the 240V KM-818 uses up to 6.4 kWh for each hour its elements are fully on. At an example rate of 15 cents per kWh, that is a ceiling of about 96 cents per hour; the 30A model at 5,200 W is about 78 cents per hour. The real cost is lower, because the controller cycles the elements. Enter your rate in the KilnMaster's firing cost feature to see the figure for each firing.
Controller and monitoring
The KilnMaster controller offers cone-fire presets for bisque and glaze, ramp-and-hold programs of up to 32 segments with 12 stored programs, diagnostics, firing cost and firing count. Current sensing reads amps per section and voltage under load, so a weak element shows up before a firing falls short. Clay-King lists the KMT-818 touchscreen version with Wi-Fi updates and a tilting mount.
Accessories and upgrades
- Furniture kit: listed above; Clay-King gives the kit a 50 lb shipping weight.
- EnviroVent 2: 140 cfm downdraft vent on a 120V outlet, with an 8 foot extension kit; see our kiln vent guide.
- Rolling stand: with an EnviroVent 2 adapter.
- KilnLink: monitoring in 1 year or 5 year plans.
- Type S thermocouple, APM elements, Easy View: Skutt upgrades.
Owner questions answered by Skutt's manual
- First firing: shelves only on 1 inch posts, cone 04, medium speed, no hold; smoke is normal.
- No vent yet: leave the top peep plug out and prop the lid 1 to 2 inches until 1,000°F (538°C).
- Shutoff: be with the kiln when it is due to turn off; cool naturally and unload at about 125 to 130°F.
- Thermocouple: replace after about 50 cone 6 or 150 cone 04 firings.
- Kiln wash: shelves and floor only, never walls or lid.
What the KM-818 does well
It offers cone 10 in a compact, 145 lb kiln on a common 40A circuit. Skutt publishes full electrical data for every version, dealers stock parts, and the warranty covers parts and labor for two years from the first retail purchase, never pro-rated. A 30A version and a 3 inch brick version give real choices without changing the controller you learn on.
Weak points
You need 240V and an electrician. Standard brick is 2.5 inch. Skutt's own documents disagree on the 240V amp figure and on the 30A model's receptacle, and dealer lead times ran 10 to 14 weeks for the made-to-order KM-818 at The Ceramic Shop in October 2026. The 30A model gives up cone 10.
The outside of a firing kiln gets hot. Keep Skutt's 18 inch clearance, keep children and pets away, and ventilate the room. Clay and glaze dust contains silica: clean wet, never dry sweep, and wear a NIOSH-approved respirator when mixing dry materials. For element or relay work, follow Skutt's manual or use a qualified kiln technician.
Who should buy, and who should skip
Buy the KM-818 if you fire every week or two, want cone 10 available, and can add a 40A, 240V circuit. Buy the KM-818-30A-3 if a 30A circuit is your limit and cone 5 to 6 is your range.
Skip it if you only have 120V (see the KM-614-3 in our electric kiln guide), or if you fill a kiln twice a week and would be better served by the KM-1027.
Alternatives
- Skutt KM-1027: 7 cubic feet on a 60A circuit.
- Olympic kilns: the Medallion MAS1823HE adds depth on a 40A circuit.
- L&L kilns: Easy-Fire e18S with hard element holders.
- Jen-Ken kilns: the 1822 is deeper but rated to cone 8.
- Best kilns for home pottery: cross-brand picks.
Sources: Skutt KM-818 product page; Skutt Ceramic Kiln and Wheel Catalog 2023; Skutt electrical installation sheet for contractors (undated, current October 2026); Skutt KM electrical spec sheet (rev. 9/13/99); Skutt KilnMaster Operating Manual (rev. 1/19/09); Clay-King KM-818 listing; The Ceramic Shop KM-818 240V 1P listing; Sheffield Pottery KM818-30A-3 listing; New Mexico Clay KM-818 listing. Specs checked October 2026.