When you go to the supermarket, you will probably find all weights, volumes, etc. in metric units, e.g. can of beans with 400 g on the side, bag of pasta with 500 g on the packet, bag of frozen chips with 1.8 kg on the packet, bottle of water labelled as 2 litres. When you see the prices for frozen vegetables and see the prices for fresh vegetables, both priced per kilogram, you can easily compare prices, both between products and between supermarkets. Supermarkets also give comparative prices, e.g. price in pence per 100 grams (see image below).
Most household products you buy are measured in metric, such as a tube of toothpaste having a volume of 100 millilitres, shampoo labelled as 250 ml, and various other bathroom products, in ml or if measured by weight, then in grams.
Despite not always having metric labels on, in the UK (and most countries in the world) all clothes have been designed and manufactured using metric measures.
All soft drinks and prepacked alcholic drinks are in metric sizes today. Wine comes in bottles sized at 750 ml, often written as 75 cl (cl = centilitres, and 10 ml = 1 cl). Beer in cans and bottles might be 440 ml, 500 ml, 660 ml or other multiples of millilitres.
Soft drinks in cans in the UK are often sold in a size of 330 ml, which is about one third of a litre. Mineral water is sold in bottles of 250 ml, 500 ml, 1 litre, 2 litres, and other metric quantities.
The food/drinks you buy will often have nutritional information on the packaging, such as how much energy, fat, protein, sodium, etc., per 100 g or per 100 ml of the product. Whether the energy value is in joules or calories, both are metric units, although joules are a better way of measuring energy.