Using a dishwasher is more hygienic than hand washing dishes - getting rid of more germs and bacteria than the old sink and sponge method.

Today, every dishwasher is given an energy efficiency grading, so you can see at a glance how economical it is. There's a huge variety to choose from too. Some of the top machines can detect how dirty your dishes are, while more basic models will still deliver a thorough, standard wash.

This guide will help you choose the best one for your needs.

Dishwasher capacity is always measured in place settings, with one place setting consisting of a dinner plate, side plate, soup bowl, cup, saucer, knife, fork and spoon. Dishwashers come in three basic sizes:

The selection of washing programmes will vary, but standard functions tend to be similar.

Main wash: a standard wash function for cleaning a full load.

Rinse only: a hot water rinse-through will prepare a load for its main wash. Rinsing removes food that could cause unpleasant smells if left to fester.

Economy: a cooler wash that uses less energy than a hot water wash.

Glass wash/delicates: premier models may have this function for delicate glass and china.

Half load: useful if you only stack your machine to half its capacity. This uses less energy than a full load wash so makes it more efficient if the machine is not full.

Dry: this function means crockery and cutlery are ready to be put away immediately after a cycle has finished. It's best to allow the contents to cool before handling, as the drying function can leave materials too hot to touch.

Timer delay: a useful feature that allows the start of the programme to be delayed. Handy for saving money as you can run your machine using a cheaper night time tariff such as Economy 7. For models that don't have a timer delay, an ordinary timer plug will achieve the same result.

By law, many domestic appliances, including fridges, freezers, washing machines, tumble dryers, dishwashers and ovens must now meet strict criteria on energy efficiency. To make it easy to recognise appliances that are energy efficient, there's a grading system, from A, the most energy efficient, to G, the least energy efficient. 

In addition to energy efficiency, dishwashers are also rated for their cleaning performance and drying performance. Like the energy efficiency rating, cleaning and drying performance are also rated from A to G, with A being the best performing, and G being the poorest.

Some models higher up the energy efficiency grading - and are generally pricier - have technology known as fuzzy logic. These machines have built-in sensors that can measure the amount of soiling in the water and alter the washing cycle accordingly.

The lower the decibel number, the quieter the machine will be. If your kitchen is open plan, or the dishwasher is near your lounge, so you may want to choose a model that runs more quietly.

How you stack crockery will affect the ability of the machine to clean it. Water jets in a dishwasher are more powerful at the base of the machine, so heavily soiled items should be stacked lower down and smaller items should be arranged in the top basket.

Clean the machine's filter regularly - if you don't the machine won't clean efficiency and will start to smell.

After installation, remember to adjust the water hardness level setting depending on the hardness of the water in your area. Your local water board will be able to advise you.

IMPORTANT: always check that a product is dishwasher-safe by reading its instructions. Lead crystal can go cloudy and mist, cast iron cookware may rust and wooden items can warp and split.