Buyer's Guide: Microwaves

justin schamotta
By Justin Schamotta


WHETHER it's the promise of a rejuvenated cup of tea, or a warming bowl of soup, the familiar "ping" of a microwave is enough to cause us to start salivating.

But while every microwave can carry out the basic reheating functions, the modern machine is all about the extras. Read on to find out exactly what microwaves can do and whether you need them to do it.

1. Type of microwave

What to consider
  • Grill microwaves don't cost much more than solo microwaves
  • Combi ovens are the most versatile, but relatively expensive

It might seem like a silly question - but what do you want your microwave to do? Is it just for reheating food, or would you rather something that can cope with more sophisticated culinary efforts?

A lesser consideration is whether the machine needs to be freestanding, or built in to your existing kitchen.

Microwave only

The simplest and cheapest type of microwave, these only use microwave energy to heat food. The basic science behind this process involves something called a magnetron.

The magnetron emits radio waves at a specific frequency, which agitate water molecules in food. As the atoms begin to vibrate, they cause friction. This generates heat, which cooks the food.

Solo microwaves (as they are sometimes called) enable us to easily cook and defrost food, or reheat leftovers.

Because of their relatively limited features, this type of microwave tends to be smaller than the rest of the machines listed here.

Microwave with grill

The addition of a grill to the standard microwave is a step up in the microwave world. They contain a built-in element that can brown the outside of food, and firm up what might otherwise resemble a wet towel.

It also means we can grill fish and meat, as well as finishing pizzas to golden perfection. Most grill microwaves come with a metal rack to bring food nearer to the element.


The combination microwave oven, like its name suggests, offers a combination of cooking options. It contains a grill, convection oven and microwave - all in one convenient unit.

These features enable a plethora of meals to be cooked - even roast dinners. Most have preset programs that automatically cook meals using each of the three methods - with the right timings.

The combi can be a good option for those of us with limited space, as it does away with the need for a conventional oven.

Integrated ovens

Integrated or built-in microwaves are for those who want a slick, streamlined kitchen, and are willing to pay the additional cost to get it.

Each of the types mentioned above are available as built-in versions, but integrated microwaves do cost considerably more than their messier freestanding cousins.

Because built-in microwaves form part of the kitchen infrastructure, they can be fitted at eye height, rather than sitting on the worktop. This makes trying to peer inside easier - and also means that small children are unable to reach them.

Retrofitting an integrated microwave isn't particularly easy, so they are most suited to people installing a new kitchen.

2. Size

What to consider
  • Capacity is measured in volume, not dimensions
  • Large capacity microwaves can occupy a lot of space
  • Grill and combi microwaves are bigger than solo microwaves
  • Make sure the turntable is big enough for your plates

Microwave capacity is measured in cubic litres, ranging from 13 litres to 42 litres. A typical family sized microwave is somewhere between 20 and 25L.

But because this is a measure of volume rather than height or width, machines with the same capacities can look quite different. Measure your largest plates and mugs to find out how you need that volume distributed in terms of height and width.

Turntable size

The majority of microwaves work by revolving the food inside on a turntable, thus exposing it evenly to the microwave radiation.

So when sizing up a microwave, do look at the turntable. Some of the smaller microwaves have turntables with a diameter of 25cm - too small to hold a typical dinner plate, which is at least 27cm in diameter.

For those hoping to knock up a Sunday roast, larger models have turntables measuring up to 34cm in diameter.

A few models do away with turntables altogether, bouncing the microwaves around inside the space rather than moving the contents around. These can be particularly space efficient, allowing you to make full use of the microwave's rectangular insides.

Interior height

If width and turntable space aren't a problem, consider whether you might also want to stack plates or balance bowls. The larger microwaves, by default, have more interior height, and many will come with a shelf arrangement enabling two dishes to be heated at once.

External size

Bearing those considerations in mind, it's still possible you'll find there are microwaves of varying sizes still vying for your attention. As they can take up valuable space on your worktop, do remember to consider the external dimensions.

Some microwaves can look almost square, while others might favour depth over height - and the more an oven can do the bigger it'll be.

For example, a solo microwave might be 44cm wide, 35cm deep and 26cm tall. A larger combi model might measure 52cm wide, 48cm deep and 31cm tall.

Also pay attention to how much clearance the oven needs. There needs to be air around the vents, and some manufacturers are quite specific about how much there should be above and to the sides.

Other factors

When considering size, also consider the other physical attributes the microwave might have or will need. For example, integrated ovens will often come with drop down doors. This can make taking food out a little easier, in part because the door can act as a shelf to rest plates and dishes on.

Freestanding microwaves, sitting on kitchen surfaces, may benefit from having a child lock to stop children interfering with cooking, or starting the oven when it shouldn't be in use.

Then there's the interior of the microwave. They may all look pretty similar, but some top end ovens will have self-cleaning linings. Known as either pyrolytic or catalytic liners, they help to prevent the build up of grease or food.

3. Power

What to consider
  • The higher the power rating, the faster the cooking time
  • Higher powered machines cost more

Since their invention in the 1940s, microwaves have become ever more powerful. There are two methods for describing the power output: a number, which is the output in watts (W), or a letter ranging from A to E.

The letter classification isn't as common or as popular, not least because it's a little unclear. In both cases, the higher the number or letter, the higher the power - and the higher the power, the faster the oven heats food.

Compare the times on the back of a ready meal to see what we mean: a single serving pasta bake may typically take five minutes to cook in a 900W microwave, but six in an 800W microwave.

The standard output these days tends to be 850W or 900W - or D and E in letter terms - although top end models now have a maximum output of 1,100W. Budget versions often produce a respectable 700W.

4. Functions

What to consider
  • Additional features cost more
  • Some functions save time, others are about cooking quality
  • Presets can help cook and defrost safely

The range of functions separates the more expensive microwaves from the cheaper ones in their category. Choosing which you need will be determined by what kind of cooking you do.

If you keep the majority of your food in the freezer, then a good defrosting feature will be indispensible. If you're something of a pizza aficionado, consider one of the microwaves with a specific pizza function.

Perhaps the most important thing is the style of control panel you opt for. Dials are easier to use when you need to change settings midway through cooking. For exact timings, touchscreens and electronic buttons are better.

Preset programmes

Some microwaves have preset programmes that affix specific cooking times to specific foods and ways of cooking. As mentioned earlier, these even include the pizza function, designed to optimally cook or reheat pizza.

Automatic cooking, reheating and defrosting

These vary from machine to machine, but most allow the user to enter the weight of the food they want to cook, reheat, or defrost. The microwave then calculates how long it needs to do the job.

Many microwaves with this feature will also allow the user to select the type of food, which can have a bearing on how long it'll need in the oven to be safe.

A new and somewhat hip sounding addition to this line up is the "chaos defrost" function. This uses random bursts of microwave radiation to further reduce defrosting time.

Other cooking modes

Newer models may also come with a steaming function, which basically emits steam into the cooking area. It's useful for cooking things like vegetables or fish.

Multiple sequence cooking isn't all that new in theory - some older microwaves can be set to go from defrosting straight into cooking. But in newer machines the available options are more subtle, allowing for more adventurous cooking.

Top end microwaves may also contain a sensor that detects moisture in the food and in the air surrounding it, and use the information it provides to adjust the overall cooking time.

5. Energy Efficiency

What to consider
  • Microwaves use less energy than conventional oven
  • Energy efficiency ratings range from A to G - A is the best

Microwaves are more energy efficient than conventional electric and gas ovens. This is because microwaves use energy to directly heat food, whereas gas and electric ovens must also heat the air inside the oven.

Tests show that when heating a like-for-like meal, a microwave used three units of energy, an electric oven used 16 and a gas oven used seven.

Microwaves are given an energy efficiency rating from A to G, with A being the most efficient. There's a great deal of variation between models - price doesn't necessarily correlate with efficiency.

6. Cost

What to consider
  • Basic microwaves start at £35
  • A grill microwave doesn't cost much more than a solo microwave
  • A combi microwave is expensive but can replace a standard oven

More than 80% of us own a microwave, according to the Department for Energy and Climate Change. The market reflects this, and there's a microwave available to suit most budgets.

At the cheaper end of the spectrum, a solo microwave can cost as little as £35, though most tend to fall within the £60-£80 bracket.

The more features the oven has, the more expensive it'll be. For example, a grill microwave is slightly more expensive than a solo microwave - with the cheapest around the £50 mark, and most costing between £80 and £100.

Taking the next step up, the cheapest combi microwave is approximately £100, but they typically retail in the region of £150 and £250.

Bearing in mind what we said about the higher cost of integrated ovens, it is possible to purchase one for between £100 and £200. That said, the average integrated microwave costs between £300 and £700 - and top of the range appliances can cost in excess of £2,000.

7. Lifespan and guarantee

What to consider
  • Microwaves last up to six years
  • Guarantees usually only last 12 months

A microwave will typically last anywhere between three and six years, according to Retra, a trade association for independent electrical retailers and servicing organisations.

A typical manufacturer's guarantee for a new microwave oven is 12 months, but some stores will extend the guarantee period for anything up to five years. Certain famous retailers offer guarantees of two years for no extra cost, but any longer than this tends to come at a price.

What's more likely is that a retailer will offer to sell you an extended warranty. Read our guide to them to understand the difference, and whether shelling out is worth it.

8. Containers

What to consider
  • Not all containers are suitable for microwaves
  • Some machines come with their own trays, dishes and bowls

Bearing these last two considerations in mind, it makes sense to only use the right equipment to cook things in or on.

As mentioned, some microwaves will come with shelf inserts for cooking plates on top of each other and grill microwaves will usually include a rack for lifting the food closer to the element.

Those who are as obsessed as we are with pizza will want to look out for special trays like the crisper plate. This helps prevent soggy bottomed quiches, as well as preserving the thin and crispy nature of the well cooked pizza.

What to use

Your best bets are heatproof glass and Pyrex, and plastic tubs labelled as microwave safe. Nonporous earthenware, pottery and ceramics are also fine. Paper plates or a simple paper towel will both work - but they can disintegrate or stick to foods if they're moist or fatty.

Even so, no container on the safe list is foolproof - we've all burned our lips on the mug despite the tea we were reheating still being on the tepid side.

What not to use

Don't use anything with metal - even a fancy trim around the top of a cup - in the microwave when using it as a microwave. At best it'll spark, at worst it'll cause a fire. Foil will shield anything underneath it from the microwave radiation, making the cooking process pointless.

Unless the packaging states that it's safe to be put in the microwave, don't use containers that were purchased with chilled or frozen foods.

They're usually designed with low melting points and may leach contaminants. If in doubt decant the food onto a plate or microwave-safe bowl.

In summary

Microwaves range widely in what they can do and how much they cost.

There's little point looking at a machine costing in excess of £1,000 when all you want it to do is heat soup. Conversely, budding Blumenthals will want something capable of a little subtlety and should expect to pay for that capability.

It really is a buyer's market out there, so you can afford to be picky.

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