Which size Rational iCombi
do I need?
6-1/1, 10-1/1 or 20-1/1: you choose the right size not by covers alone, but by what you need out of the unit at the same time. This guide shows how to settle that in five questions.
By JMGT Commercial Kitchen Equipment · Official Rational dealer · Last updated 1 October 2026
In short
Calculate for your busiest day. For the iCombi Pro, Rational gives roughly 30 to 100 meals per day for a 6-1/1, roughly 80 to 150 for a 10-1/1 and roughly 150 to 300 for a 20-1/1. If you are at or above the upper limit, or cannot afford to stand still when a fault occurs, choose the next size up or two smaller units.
What does Rational say per model?
Below are the official capacity indications from Rational for the iCombi Pro. The number of levels and the GN format are fixed per model; meals per day is a guideline.
| Model | Capacity | Meals per day | Typical kitchen |
|---|---|---|---|
| iCombi Pro XS | 6 x GN 2/3 | approx. 20 - 80 | Bar, small venue, supplementary unit, little space |
| iCombi Pro 6-1/1 | 6 x GN 1/1 | approx. 30 - 100 | Restaurant, lunch cafe, bistro, small hotel |
| iCombi Pro 10-1/1 | 10 x GN 1/1 | approx. 80 - 150 | Busy restaurant, hotel, staff canteen |
| iCombi Pro 20-1/1 | 20 x GN 1/1 | approx. 150 - 300 | Large kitchen, care, catering |
| iCombi Pro 6-2/1 | 6 x GN 2/1 | approx. 60 - 160 | Production with large pans, compact footprint |
| iCombi Pro 10-2/1 | 10 x GN 2/1 | approx. 150 - 300 | Production kitchen, care, catering |
| iCombi Pro 20-2/1 | 20 x GN 2/1 | approx. 300 - 500 | Central kitchen, large-scale catering, hospital |
Source: RATIONAL AG, iCombi Pro model page (meals per day). The typical kitchen column is our own classification. The iCombi Classic is available in several of the same sizes; the selection logic is the same.
Not just covers: count your cooking jobs
Two kitchens with the same number of covers can need different sizes. A restaurant that takes one main course per table out of the oven loads the unit differently from a kitchen that gets meat, vegetables, fish and a dessert out of the combi oven in the same service. The number of levels is your working capacity: the more cooking jobs at once, the more levels you need.
Use these five questions as a checklist before you choose a size.
1. Peak day How many meals or covers do you serve on your busiest day, and in what time window? A short, hard peak needs more levels than the same volume spread across the day.
2. Simultaneous cooking jobs How many different products have to come out of the unit within the same service, such as meat, vegetables, fish and regeneration? Each cooking job needs its own levels.
3. Pan format Do you work with GN 1/1 or with large pans and trays? That decides between 1/1 and 2/1.
4. Space and connection Table-top or floor-standing, clearances, route into the kitchen, electricity or gas, water and drain. The physical situation often limits the choice before the budget does.
5. Downtime risk What happens in your kitchen if this unit is down for a day? That decides whether to consider a second, smaller unit.
GN 1/1 or 2/1: look at your pans
The racks of a 1/1 unit take GN 1/1 pans, those of a 2/1 unit take double the size. A 2/1 pays off when you work structurally with large pans or whole batches at once, as in care, production and catering. For most restaurants, hotels and staff canteens 1/1 is the logical size, because plates, pans and workflow are set up around it.
The full comparison by format, including Pro or Classic and new or used, is in which Rational suits my kitchen. If a 6-1/1 no longer fits your space, read the iCombi Pro XS review.
Placement and connection: table-top or floor-standing
The smaller models, up to and including the 10-level units, are normally placed as table-top units on a stand or sturdy worktop. The 20-level models are floor-standing and are often used with a loading trolley. That changes your kitchen layout: a floor-standing unit needs a level, load-bearing floor and enough room to roll a trolley in and out.
The connected load rises with size. Electric is the standard and usually the simplest to install; gas is possible where gas infrastructure exists. Whether your existing distribution board can carry the extra load more often decides the size in practice than the budget does. Have your installer check this in advance. Also check the route into the kitchen: a unit that does not fit through the door is an expensive lesson.
Take the exact dimensions and connected loads per model from the Rational technical data. We check them for your situation during a site survey. More on the requirements in installing a combi oven: power, water and drain.
One large or two small combi ovens?
A 10-1/1 gives ten levels in one chamber. Two 6-1/1 units give twelve levels spread across two chambers. On paper that is similar; in the kitchen it is not.
Advantages of two smaller units. Redundancy: if one unit is down, you carry on with the other. Flexibility: two cooking jobs with different programs and temperatures at the same time, and on quiet days only one unit runs. Staged investment: you buy the second unit when revenue justifies it.
Advantages of one large unit. Less floor space, one connection and one service visit, and it is stronger with large batches back to back, such as in catering, banqueting or production kitchens with trolleys.
As a rule of thumb: if the combi oven is the core process of your kitchen and you cannot afford downtime, consider two units. If you use it as one of several workstations, one well-chosen unit is usually enough.
What we see in the workshop and at kitchen checks
In our workshop and at kitchen checks one mistake comes up more often than any other: choosing too small. The size is based on the average, while the kitchen has to work in two rounds on Fridays and Saturdays. The unit is then not too small for the week, but too small for the moments when the money is made.
The second pattern is the second unit that turns out to be needed after all. Kitchens that consider a second unit after the first fault would often rather have bought two smaller ones than one large one. That is why we always ask first about your busiest day, your simultaneous cooking jobs and what a day of downtime means for you, and only then about the model.
And if it becomes a used unit?
Size first, then new or used. At JMGT, used units are checked and tested by our own technicians, and we carry out service on Rational units ourselves. Stock per size changes, so see used equipment for what is available now, or tell us the size you want. What matters with used units is covered in buying a used Rational.
You can compare the versions on the pages iCombi Pro and iCombi Classic, with the overview at Rational. If you are torn between those two, see iCombi Pro vs iCombi Classic.
Next step
Send us your covers on the busiest day, your cooking jobs per service and a photo of the intended spot. We will tell you which size fits and whether it fits your kitchen.
Frequently asked questions
What size combi oven do I need for my restaurant?
Start from your busiest day, not the average. For the iCombi Pro, Rational gives a guideline per model: 6-1/1 for roughly 30 to 100 meals per day, 10-1/1 for roughly 80 to 150 and 20-1/1 for roughly 150 to 300. Then look at how many different cooking jobs you need out of the unit at the same time within one service: that decides whether you sit at the low or high end of that range.
Combi oven 6-1/1 or 10-1/1: what is the difference in practice?
A 6-1/1 has six levels for GN 1/1, a 10-1/1 has ten. The difference is mainly how many pans you can cook at once. A 10-1/1 takes about one and a half times as many pans per round and runs calmer during peaks, while a 6-1/1 is more compact. If in doubt: if you regularly need a second round on your busiest day, choose the 10-1/1.
How many covers can a combi oven handle?
According to Rational, for the iCombi Pro: XS (6 x 2/3 GN) roughly 20 to 80 meals per day, 6-1/1 roughly 30 to 100, 6-2/1 roughly 60 to 160, 10-1/1 roughly 80 to 150, 10-2/1 roughly 150 to 300, 20-1/1 roughly 150 to 300 and 20-2/1 roughly 300 to 500. These are guideline values. Your menu, number of courses and peak pattern decide what actually fits your kitchen.
Is one large combi oven better than two small ones?
Not necessarily. Two smaller units give redundancy: if one is down for maintenance or a fault, the kitchen does not stop. You can also run two cooking jobs with different programs and temperatures at the same time. One large unit wins on floor space per level and when you run large batches back to back, for example in catering or banqueting.
What should I check for placement and connection?
The smaller models are normally placed as a table-top unit on a stand or worktop, the 20-level models as a floor-standing unit. Check clearances, the route into the kitchen, floor load, the electrical or gas connection, the water connection and the drain in advance. The connected load rises with size; have your installer check it beforehand.
Can I also choose a used Rational in a different size?
Yes. The size decision is the same for a used unit as for a new one. At JMGT, used units are checked and tested by our own technicians. Stock per size changes; tell us the size and version you want and we will see what is available.