The metric system around the world: a practical guide for travellers

Nearly every country uses the metric system as its official system of measurement. The United States is the notable exception in everyday life; Liberia and Myanmar are often listed alongside it, though both have taken steps toward metric. Even in metric countries, older units linger: the UK posts road distances in miles and serves beer by the pint.

On the road

Speed limits outside the US and UK are in km/h. Common limits translate as follows:

Fuel is sold by the litre, and fuel economy is quoted in litres per 100 km — lower is better. Because it is the reciprocal of mpg, you cannot convert it with a single multiplier: 30 US mpg is 7.84 L/100 km, while 40 mpg is 5.88. See the fuel consumption converter. And remember UK mpg uses imperial gallons, about 20% larger than US ones.

Weather

Forecasts are in degrees Celsius almost everywhere except the US. A quick reference: 0 °C is freezing, 10 °C is jacket weather, 20 °C is mild, 30 °C is hot. For exact values use the Celsius to Fahrenheit converter.

Body measurements

Height is given in centimetres in most countries (180 cm ≈ 70.87 in, or about 5 ft 11 in) and weight in kilograms. The UK and Ireland often still use stones for body weight: 1 st = 14 lb = 6.35029 kg.

Food and shopping

Deli counters sell by the 100 g or kilogram (1 kg = 2.205 lb), drinks by the litre or 33 cl can. Recipes list grams and millilitres, and oven temperatures in °C — the cooking conversion guide has a chart.

Electricity

Most of the world uses 220–240 V mains at 50 Hz, while North America uses 120 V at 60 Hz. Many chargers accept both (check for “100–240 V” on the label); heating appliances usually do not.

Money

For currencies, use a source that shows when the rate was published. Our currency converter displays daily European Central Bank reference rates with their date — remember that card and kiosk rates will be less favourable.