Before ordering a speed oven, record six figures: external width, height and depth, usable cavity width, height and depth, minimum cutout depth, boxed dimensions and weight, and the service clearance and door swing allowance around the final position. Most manufacturers list these in millimetres, though many datasheets also carry inch equivalents, so note both where they appear. The single action that prevents a failed installation is measuring the actual space, not the cabinet opening, and checking it against the manufacturer’s cutout diagram rather than the product photo.
TL;DR:
- Confirm the actual cavity dimensions and manufacturers’ cutout diagrams rather than relying on external or product photos to ensure correct installation fit.
- Verify boxed dimensions and weight because they determine doorway clearance and delivery feasibility more than the net or external size.
- Measure final site space, including clearance for door swing, shelving, and electrical connections, against the manufacturer’s specified minimum cutout and clearance requirements.
- Consider ventilation needs carefully, noting that ventless models still require fire and health approval, and ducted units must meet duct length and airflow guidelines.
- Use manufacturer builder specs as the primary reference for all dimensions to prevent common installation errors like insufficient clearance or wrong cutout sizes.
Table of Contents
- Typical external and cavity dimensions across speed oven classes
- Cutout, mounting and clearance requirements for built-in installations
- How to measure your kitchen and verify a speed oven will fit
- Venting, extraction and service access considerations
- Practical notes from The Commercial Oven Store on planning checks
- Editorial take: why the spec sheet matters more than the showroom photo
- How The Commercial Oven Store can help with measuring, supply and installation
- Sources
- FAQ
Typical external and cavity dimensions across speed oven classes
Speed ovens span a wide range of footprints, and the external size tells you almost nothing about how much usable cooking space sits inside. A compact countertop unit might have a similar width to a mid-size built-in model but a far smaller cavity, because casing, fans and magnetron housings eat into the available space differently across brands.
Countertop compact units typically run from around 350mm to 450mm wide, suited to low-volume service points such as coffee shops or grab-and-go counters. Built-in or under-counter compact models generally sit between 420mm and 760mm wide, the range covering most single-door speed ovens fitted into a line of equipment. Larger professional speed and convection hybrids can reach 600mm to 1,000mm, closer in scale to a compact combi oven than a countertop appliance.
Cavity size is the number that actually determines what you can cook and on what tray. The Merrychef conneX12 spec sheet lists an oven net size of 619mm high by 356mm wide by 641mm deep, with a cavity of 305mm by 305mm, sized for a 12 inch by 12 inch tray. That is a useful reminder that external depth and cavity depth are not the same figure: the conneX12’s overall depth of 641mm includes housing, door clearance and control panel that never touch the food.
Other common cavity examples include chambers around 315mm by 320mm by 210mm and smaller 300mm by 300mm by 130mm compartments, both typical of compact models built for single-tray or half-size GN pans. If your kitchen runs standard 1/1 GN trays, check the cavity dimensions specifically, because a wide external cabinet does not guarantee a wide enough opening for the tray you actually use.
| Class | Typical external width | Representative cavity example | Typical use |
|---|---|---|---|
| Countertop compact | 350 to 450mm | 300 x 300 x 130mm | Coffee shops, small service points |
| Built-in / compact | 420 to 760mm | 315 x 320 x 210mm | Standard commercial kitchens |
| Speed/convection hybrid | 600 to 1,000mm | 356 x 305 x 641mm (conneX12 net) | High-volume or multi-tray service |
Boxed dimensions matter just as much as either figure once delivery day arrives. The Merrychef conneX12 spec sheet shows a boxed size of roughly 855mm by 520mm by 820mm for a net oven of 619mm by 356mm by 641mm, a substantial jump in every dimension.
- Confirm external width and depth against your counter or cutout space before shortlisting a model.
- Check cavity width and depth against the tray or pan size your kitchen already uses.
- Treat boxed dimensions as the number that decides whether the oven clears your doorway, not the net size.
- Note that a wider external cabinet does not always mean a wider cooking cavity.
Cutout, mounting and clearance requirements for built-in installations
A product’s external dimensions and its required cutout are two different numbers, and confusing them is one of the most common planning errors in commercial kitchen fit-outs. The cutout is the minimum opening a cabinet or housing must provide, and it usually allows a small margin around the appliance for airflow, cable routing and door operation, so it can differ from the oven’s stated external size by a meaningful margin.
Builder specification sheets are the authoritative source for this figure. The LG builder spec sheet for a compact built-in speed oven shows a minimum cutout width of around 723.9mm and a maximum of 727.0mm, with a minimum cutout depth near 596.9mm. The Fisher & Paykel 30 inch Series 9 builder spec similarly publishes minimum cutout depth, cutout height and a recommended installation height, figures that installers should copy verbatim from the diagram rather than estimate from the product photo.
One figure worth writing on the site plan itself: a compact built-in speed oven can require a cutout width within a narrow range near 724mm, according to the LG builder spec sheet. A cabinet built even a few millimetres under that minimum will not accept the unit regardless of how the external dimensions compare.
Mounting options affect what clearance you need beyond the cutout itself.
- Countertop placement needs a stable, heat-tolerant surface and rear clearance for cable and airflow.
- Built-in installation requires the cabinet cutout to match the manufacturer’s minimum width, height and depth, with no compression from trim or corner mouldings.
- Mounting on a plinth or base frame raises the working height and needs the frame rated for the oven’s operating weight, not just its static weight.
- Stacked installations need a support shelf or stacking kit rated for the combined weight of both units, plus clearance for the upper unit’s door swing.
Boxed size and weight decide whether the appliance even reaches the installation point. A narrow stairwell, a tight corridor turn or a service lift with a shallow door can stop a delivery before it reaches the kitchen, so record the boxed weight for manual handling planning alongside the boxed dimensions from the manufacturer’s datasheet.
How to measure your kitchen and verify a speed oven will fit
Getting this step wrong is the most common cause of a delivery that cannot be installed on the day. Work through the checks in order, and treat each one as a pass or fail against the manufacturer’s own figures rather than an approximation.
- Measure width, height and depth at the exact final location, not at a similar spot nearby, and record any skirting, benchtop overhang or wall projection that reduces the usable space.
- Check above-counter shelving, extraction canopies or cupboards for clearance against the oven’s full height, including an open door where the model requires top loading or viewing access.
- Measure the delivery route from the entrance to the installation point, including doorway widths, lift internal dimensions and any corridor turns, using the boxed dimensions rather than the product’s net size.
- Confirm rear clearance for cable access and the working space the manufacturer recommends for routine maintenance and filter or panel removal.
- Check the door swing radius at the final position to confirm the appliance can open fully without striking a wall, handle or neighbouring unit.
- Verify the electrical connection: locate the distribution board, confirm cable entry position, and establish whether the appliance needs a fixed spur connection or a standard plug outlet.
Pro Tip: Take a tape measure and the manufacturer’s cutout diagram to site together, and mark the exact cutout footprint on the floor or worktop before ordering, so any last obstruction shows up while there is still time to change the plan.
Venting, extraction and service access considerations
Ventilation requirements shape where a speed oven can physically sit in a kitchen, sometimes more than its footprint does. Some models use catalytic converter technology and are marketed as ventless, which the Merrychef conneX12 spec sheet notes can allow front-of-house placement without external extraction in certain configurations. Others rely on ducted extraction and need siting under, or close to, a canopy hood.
A ventless claim is not the end of the assessment. Local fire safety and environmental health requirements still apply to any cooking appliance, and it is worth confirming compliance for the specific site before assuming an oven can be installed without extraction.
- Ventless catalytic units still need local fire and environmental health sign-off, even where the manufacturer describes them as extraction-free.
- Extracted units need siting close enough to a hood or duct run to meet the manufacturer’s maximum duct length and clearance guidance.
- Air intake and exhaust points should stay clear of walls, shelving or neighbouring equipment, matching the clearances shown on the builder spec.
- Service access should allow for removable panels, filter changes and a realistic working height for staff carrying out routine cleaning or maintenance.
Getting the ventilation decision right at the planning stage avoids a scenario where an oven is installed, wired and plumbed, only to fail a fire safety inspection because the extraction path was never checked against the specific model’s requirements.
Practical notes from The Commercial Oven Store on planning checks
Across installation work, the same handful of measurement mistakes come up repeatedly, and nearly all of them are avoidable with a five-minute check against the manufacturer’s own documents.
The most frequent error is reading cutout depth as if it were cabinet depth, when the two are rarely identical once trim, door clearance and cable routing are accounted for. A close second is ignoring boxed dimensions entirely, then discovering on delivery day that the packaged unit will not clear a doorway or lift that the net oven would have passed through easily. A third is leaving no rear service clearance, which turns a routine filter change into a job that requires pulling the whole unit forward.
A workable measurement record for any site visit should include:
- Final location width, height and depth, measured at the exact spot, not an adjacent bay.
- Delivery route doorway and lift dimensions, checked against boxed size rather than product size.
- Boxed dimensions and weight, recorded from the manufacturer’s datasheet.
- Electrical connection point position and type, fixed spur or plug outlet.
- A photograph of the intended site, taken with a tape measure in frame for scale.
Support for this process is available from providers offering site surveys, installation services and expert advice, alongside flexible payment options for kitchens that need to spread the cost of a new appliance.
Simon
Editorial take: why the spec sheet matters more than the showroom photo
Most buying guidance for commercial kitchen equipment focuses on capacity, cook time and menu range, and treats dimensions as an afterthought to check once the decision is already made. That ordering is backwards. A speed oven that cooks brilliantly but will not clear your delivery lift, or will not leave enough rear clearance for a filter change, is not a viable option regardless of its performance.
The conventional advice, measure the space and pick a model that fits, undersells how many separate figures that actually requires: external size, cavity size, cutout minimum and boxed size are four different numbers, and a model can pass on three and fail on the fourth. The habit worth building is treating the manufacturer’s builder spec as the reference document from the start of the search, not a final check before payment.
If you prioritise one thing, make it the cutout diagram over the marketing photo. It is the only document that tells you, in the manufacturer’s own numbers, whether the unit will physically go where you intend to put it.
— Simon
How The Commercial Oven Store can help with measuring, supply and installation
Working out cutout depths, boxed dimensions and clearance requirements is easier with someone who has fitted the equipment before. The Commercial Oven Store offers expert advice on matching a speed oven, combi oven or convection oven to a specific kitchen layout, drawing on genuine manufacturer specifications rather than guesswork about what “should” fit. Flexible payment through iwocaPay means a kitchen does not need to find the full purchase price upfront to move ahead with a fit that has already been checked against the site.
- Expert advice on matching cavity size, cutout dimensions and clearance needs to your kitchen layout.
- An installation service that accounts for delivery routes, service access and electrical connection points.
- Flexible payment options through iwocaPay for spreading the cost of a new oven.
- A range of commercial ovens from established manufacturers to compare against your measured requirements.
If you are ready to move from measurements to a shortlist, visit The Commercial Oven Store to request a site survey or speak with the team about a measurement checklist tailored to your kitchen.
Sources
The figures in this article come directly from manufacturer builder specs and datasheets, which remain the most reliable source for exact dimensions ahead of purchase.
- Merrychef conneX12 spec sheet
- LG builder spec sheet (example cutout dimensions)
- Fisher & Paykel 30" Series 9 builder spec
FAQ
What are the common problems with speed ovens?
The most common installation problems involve mismatching cutout depth with cabinet depth, underestimating boxed dimensions for delivery, and leaving insufficient rear clearance for servicing. Checking the manufacturer’s builder spec against the actual site, rather than the product photo, prevents most of these issues before ordering.
What is the size of the Miele speed oven?
Exact external and cavity dimensions vary by model and are best confirmed on Miele’s own product specification sheet before ordering. As a general approach, always check the manufacturer’s listed external, cavity and cutout figures together rather than relying on a single headline size.
What are the standard dimensions of ovens?
There is no single standard size across commercial ovens, since dimensions vary by class, from compact countertop speed ovens around 350mm to 450mm wide, to larger combi and convection ovens that can exceed 1,000mm. The Merrychef conneX12 spec sheet shows a net oven size of 619mm by 356mm by 641mm as one representative example.
How big is a combi oven?
Combi oven size depends heavily on capacity, with professional models such as the RATIONAL iCombi Classic showing a cooking system body of 850mm by 754mm by 775mm and a total footprint of 850mm by 804mm by 842mm, according to the iCombi Classic datasheet. Always check the total dimensions, not just the body size, since handles, hinges and control panels add to the footprint.
Should I trust the cutout depth or the product depth when planning a built-in installation?
Use the cutout depth from the manufacturer’s builder spec, since it accounts for door clearance, cable routing and airflow that the product’s raw depth figure does not include. The Fisher & Paykel builder spec and similar documents list this figure explicitly for exactly this reason.