Product Inspector
Advice Microwaves Calculator

Microwave size calculator

Estimate the litre capacity and plate fit that suit the number of people it normally serves before you compare solo, flatbed and combination microwaves.

Size estimate

Choose a microwave that fits your plates and counter

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1

Choose the main use

2

Measure the plate and usual cooking load

For a turntable microwave, the plate needs roughly 2cm of extra diameter so it can rotate without catching. Flatbed models do not need a turntable, but you should still compare the internal width and depth.

Litres are useful, but plate diameter and internal width decide whether your usual dinner plate, bowl or ready-meal tray will actually fit.

Count the people whose food it regularly handles at one mealtime, rather than everyone in the household if they usually reheat separately.

Measure straight across your widest dinner plate, rim to rim. For turntables, allow a little extra so the plate can rotate.

3

Check the counter width

Measure the usable space where it will sit, allowing for the door, vents and any wall cupboards.

The result updates automatically.

Calculator result

Start around 17-22 litres

Based on 2 people, a 27cm dinner plate and reheating use. For turntable models, compare the turntable diameter as well as the litre figure.

Use this as a starting point when comparing models. A flatbed base, tall bowls, room for the door and space around the vents can make two microwaves with the same litre size feel very different.

Suggested size
17-22 litres
Turntable size
29cm or wider
Width check
Compare the external width, then check the model depth, door and ventilation clearance.

A straightforward solo microwave should be enough.

Why litres are not the whole answer

The litre size is useful, but your plates still need to fit and the door needs room to open. A wide dinner plate may need a bigger microwave or a flatbed model, even when the litre number looks large enough.

Read what size microwave you need for the fuller capacity guide, or compare solo and combination microwaves before choosing extra cooking modes.

How to measure plate fit

Measure straight across the widest dinner plate you use, including the rim. For a turntable microwave, leave a little extra so the plate can rotate without clipping the walls. For a flatbed microwave, check the internal width and depth rather than assuming the litre figure tells you enough.

When to choose a larger microwave

Choose a larger microwave if you regularly heat family plates, use large bowls or want grill and oven-style cooking. Larger models need more space around them and can take over a small counter.

Solo, flatbed or combination?

A solo microwave is usually the straightforward choice for reheating, drinks and defrosting. Flatbed models can make better use of the internal floor area because there is no turntable. Combination microwaves add grill or convection cooking, but they are usually bulkier and need more ventilation space.

When a compact model is enough

A smaller solo microwave can be the best value for reheating, drinks, porridge and simple leftovers, especially where counter depth and storage matter more than cooking flexibility.