How do I choose a microwave, and what do the wattages mean?

Microwave specifications carry two wattages and shoppers are routinely quoted the wrong one. Beyond that, the useful differences are dull and physical: how big a plate fits on the turntable, whether the door opens the way your kitchen needs, and whether the controls let you set a power level without four presses. Everything else is a feature list.

Step by step

1. Separate the two wattage figures.Cooking output — often 700, 800, 900 or 1000W — is the microwave energy delivered to the food and is what recipes and packet instructions mean. Input power, sometimes on the door sticker or rating plate, is what the appliance draws from the socket and is considerably higher. Only the output figure is comparable between machines.
2. Pick an output that matches packet instructions.UK packaging is usually written for 800W with a conversion table for others. An 800W machine follows the packet exactly. A 900 or 1000W machine is faster but needs the times shortening. Below 700W everything takes noticeably longer and reheating becomes a chore.
3. Measure your dinner plates and check the turntable.Capacity in litres is a poor guide, because much of it is height you cannot use. The number that matters is turntable diameter, and whether a full dinner plate rotates without catching the walls. Take a plate to the shop, or measure the turntable in the specification.
4. Decide solo, grill or combination.Solo microwaves reheat, defrost and cook. Grill models add a top element for browning. Combination models add a convection oven and can genuinely bake and roast. Each step up costs money, cavity space and complexity; buy the step you will actually use.
5. Choose the format: freestanding, built-in or over-the-hob.Freestanding is cheapest and easiest to replace. Built-in gets it off the worktop but ties you to a trim kit and a specific aperture. Over-the-hob combined microwave-hoods exist and are a compromise on both jobs — a poor hood and an awkwardly high microwave.
6. Check the controls before anything else on the panel.You will set time and power thousands of times. A dial for time is faster than a keypad; a dedicated power-level key is faster than a menu. Auto programmes are used once and forgotten. This is the specification point that most affects daily satisfaction.
7. Check the door handle and which way it opens.A pull handle is easier with full hands than a push-button latch. Almost all doors hinge on the left, which matters if the machine will sit in a corner or beside a wall. Some models offer a drop-down door, which suits a built-in at chest height.
8. Look at the interior finish and the turntable removal.Stainless interiors clean better than painted ones and do not chip. A turntable and roller ring that lift straight out are far easier to wash than a fixed flatbed, though flatbed models take a bigger dish.
9. Ignore inverter marketing unless you defrost a lot.An inverter microwave genuinely varies the magnetron output rather than switching it on and off, which gives more even defrosting and gentler simmering. It is a real difference and it matters most to people who defrost meat regularly. For reheating it changes very little.

Tips

• Write your microwave's output wattage on a label on the front. Every packet instruction becomes a straight read rather than a conversion.
• A flatbed microwave takes a rectangular dish that a turntable model will not rotate. If you regularly reheat large oven dishes, that alone can decide it.
• Check the model has an interior light you can see through the door with the light on. A surprising number are dim enough that you cannot see the food boiling over.
• If it is going under a wall unit, check the ventilation clearance in the manual. Microwaves vent from the back or side and boxing one in causes cut-outs.

Common mistakes

• Comparing input wattage between models — Input power tells you what it draws from the socket, not what reaches the food. Two machines with the same input can have quite different outputs, and only output is what recipes mean.
• Buying on litres — Cavity litres include unusable height. A 25-litre machine with a small turntable may not rotate a dinner plate that a 20-litre model handles fine.
• Buying a combination model to reheat — For reheating, a solo microwave does exactly the same job for far less money and with a simpler control panel. Combination is worth it only if you will actually bake or roast in it.

Alternatives

• Solo microwave, 800 to 900W: Reheating, defrosting and microwave cooking. The right answer for most households and the cheapest to replace when it fails.
• Microwave with grill: Adds a top element for browning cheese or finishing a dish. A modest price step and genuinely useful if you reheat a lot of baked food.
• Combination microwave oven: Adds convection so it can bake and roast. Effectively a small second oven, useful in a one-oven kitchen, with a busier control panel.
• Inverter microwave: Varies magnetron output rather than duty-cycling it. Noticeably better defrosting and low-power work, at a premium.

Questions people ask