Metrication in Canada is the conversion of Canada from imperial units to the metric system. A federal program, coordinated by the Metric Commission, began in 1970 and during the following decade converted weather reporting, road signs, fuel sales and product labelling to metric units. The Commission was abolished in 1985, ending active government promotion of metrication.
All units of measurement in Canada are defined on the basis of the SI, and prepackaged goods sold to consumers must declare their quantity in metric units. Imperial units nevertheless remain legally defined under the Weights and Measures Act and may be used alongside metric units.
In everyday life Canadians use a mix of both systems. Temperature, fuel, speed limits and road distances are metric, while personal height and weight, cooking, construction materials, and the advertised prices of meat and produce often remain imperial. The continued use of imperial units reflects historical ties with the United Kingdom, supply chains shared with the United States, and opposition to metrication during the transition period. Surveys have found that most Canadians accept this mixture and few want to return to imperial units, although older Canadians are more likely to favour imperial.
Before metrication
Until the 1970s, Canada used the imperial measurement system, set out as "Canadian units of measurement" in Schedule II of the Weights and Measures Act. These units have the same names and values as United States customary units, except for measures of volume such as the gallon. Before metrication, gasoline was sold by the imperial gallon (about 4.55 litres), and in trade with the United States it was often unclear whether a figure in gallons referred to the US gallon (3.79 litres) or the imperial gallon.
Metrication program (1970–1985) The Metric Commission The Liberal government of Pierre Trudeau began implementing metrication in 1970. The Metric Commission was established in 1971, after industry had called for Canada to drop imperial measures, to plan and coordinate the change. It was headed by Stevenson Gossage. Weather reporting was deliberately converted first, a strategy later credited with helping the public adjust.
Changeover
Conversion proceeded sector by sector: April 1975: Celsius replaced Fahrenheit for weather temperatures. September 1975: rainfall began to be measured in millimetres and snow in centimetres. 1976: prepackaged food products were required to declare their mass or volume in metric units.Food Labelling for Industry April 1976: wind speed, visibility and barometric pressure were reported in metric units, with pressure given in kilopascals rather than the hectopascals (millibars) used in most other countries. September 1977: over the Labour Day weekend, every speed limit sign in the country was changed from miles per hour to kilometres per hour, under a 1972 agreement among the provinces. New cars were required to have speedometers showing km/h and odometers in kilometres, and distances on road signs were converted over the following months. 1979: gasoline pumps changed from imperial gallons to litres. 1980: milk was fully metricated.
Opposition Metrication met resistance. More than three dozen Progressive Conservative Members of Parliament championed petitions against it carrying thousands of signatures, and after the metrication of gasoline and diesel sales, 37 of them opened a "freedom to measure" gas station in Carleton Place, Ontario, selling fuel in both imperial gallons and litres. Peterborough, Ontario, one of the government's three test centres for the program, became a centre of opposition, and its Member of Parliament, Bill Domm, was one of the country's most outspoken opponents of metrication; he said people were ready to go to jail over the issue.
A few government employees lost their jobs over their opposition. Neil Fraser, a Revenue Canada official who publicly opposed mandatory conversion, was dismissed for "conduct unacceptable for a public servant".
Training in metric conversion was not universal. On July 23, 1983, Air Canada Flight 143, known as the Gimli Glider, ran out of fuel in flight after the fuel load was calculated in pounds rather than kilograms, a mistake to which poor metrication training contributed.
End of the program After the election of Brian Mulroney's Progressive Conservative government in 1984, the Metric Commission was abolished on March 31, 1985. This ended active promotion of metrication. A ruling at the start of 1985 gave store owners the choice of selling in metric or imperial units, and many retailers returned to pricing by the pound, partly because a price per pound looks lower than the same price per kilogram.
After 1985 The Weights and Measures Act remained in force after the Commission's abolition. It provides that all units of measurement used in Canada are determined on the basis of the SI, and permits trade in any unit set out in its schedules: the SI units and customary units used with them, such as the litre and hectare, and the imperial "Canadian units". Old French units may still be used to describe land in Quebec originally granted under seigneurial tenure. The Act is administered by Measurement Canada, the federal agency responsible for legal metrology.
In 2005 the Ontario Ministry of Education changed the secondary school mathematics curriculum to allow imperial units to be taught alongside metric units, a departure from earlier efforts to teach metric only. The change reflected the reluctance of much of the private sector to metricate, which had left students unprepared for the units used in the workplace. Many other provinces and territories also include imperial units in their curricula.
Current status of metrication in Canada Canada is officially metric, and metric units are standard in law, weather reporting, road transport and product labelling. Imperial units remain common for personal measurements, cooking and construction, and for historical reasons in land surveys and railways. Many everyday activities use both systems.
+ Units in common use in Canada (summary of the sections below) Mainly metric Mixed Mainly imperial Road signs, speed limits and fuel salesWeather reportsLabelling of prepackaged goodsHospital records and lab results Pricing of meat and produceCooking and recipesPackage sizes (imperial sizes labelled in metric) Personal height and weightBuilding materials and home sizesMainline railwaysPrairie land surveys, grain and cattlePaper sizes
Transport Road Canadians buy gasoline in litres, observe speed limits in km/h and read distances in kilometres on road signs and maps. Speedometers and odometers are metric, although most speedometers also show smaller figures in miles per hour. Natural Resources Canada publishes fuel efficiency for new vehicles in litres per 100 kilometres and in miles per imperial gallon, and dealer window stickers often include miles-per-gallon figures.
Rail Mainline railways, including Canadian National, Canadian Pacific Kansas City and commuter rail services, measure trackage in miles and set speed limits in miles per hour, while subways and light rail systems use metric units. Railways describe train length and height in feet and train mass in short tons, and railcars show weights in both systems.
Air Luggage limits at Canadian airports are given in metric units with imperial conversions.Carry-On Baggage As in the United States, runway lengths are given in feet and speeds in knots,1.8. Units of Measure and, as in many metric countries, altitude is given in feet.A Common European Transition Altitude Aviation fuel is measured in metric units.
Shopping and packaging Labelling and pricing Net quantity declarations on prepackaged products sold to consumers must be stated in metric units. The mandatory Nutrition Facts table uses metric units for basic nutrients, although serving sizes can be described in any unit, such as a can or a cup.
Meat and produce are commonly advertised per pound, but are sold at the checkout by the kilogram or per 100 grams. The price of a steak, for example, is typically advertised per pound while the package is priced per kilogram. Fruit and vegetables are usually advertised by the pound, with the price per kilogram shown in smaller type. More expensive items such as deli meats and fish are often priced per 100 grams. Research at Concordia University found that shoppers perceive food as cheaper when the price per pound is emphasized, even though the receipt is always in kilograms.
Package sizes Many products are made in imperial sizes but labelled in metric units, a practice known as "soft metric". Butter, for example, is sold in 454-gram packages, equivalent to one pound; under "hard metric" sizing it would come in 500 g packages. After a manufacturer lost market share when it switched aluminum foil from 25-foot to 10-metre rolls, it returned to soft metric, labelling the roll "25 feet" with the metric equivalent in small print. Fast food chains based in the United States often use US customary sizes converted to metric, so a 20 US fluid ounce soft drink bottle is labelled 591 mL, or occasionally rounded to 600 mL.
Beer in bottles is 12 imperial fluid ounces (labelled 341 mL), but beer in cans is 12 US fluid ounces (labelled 355 mL). A larger bottle is labelled . The traditional Canadian soft drink can held 10 imperial fluid ounces (284 mL), later marketed as 280 mL, and was displaced by the US-derived 355 mL size only in the early 1990s.
A 750-millilitre bottle of spirits is known in Canada as a "two-six" or "twenty-sixer", a name that survived metrication from the pre-metric 26-ounce bottle.
Home and personal life Weather and cooking Celsius is almost universal for weather, and outdoor signs usually display Celsius. Outdoor window thermometers often show both scales, and thermostats may display either. Environment Canada offers an imperial option alongside its metric forecasts.Environment Canada weather in imperial units and Environment Canada weather in metric units
Cooking uses both systems. Fahrenheit is still common for oven temperatures, because many kitchen appliances are imported from the United States, and recipes mix grams, millilitres, cups, ounces and tablespoons.
Height, weight and health Canadians commonly use imperial units for personal height and weight. Newborns are weighed in kilograms in hospital, but birth weight and length are usually announced in pounds, ounces and inches. Driver's licences give height in centimetres, but many people describe themselves in feet, inches and pounds.
Metric units generally take precedence in health care, although some differ from those used in the United States: blood cholesterol, for example, is measured in millimoles per litre in Canada but in milligrams per decilitre in the United States. Most hospitals officially record height and weight in metric units, but many physicians chart them in imperial units, and most growth charts show both.Is My Child Growing Well? Dietitians use kilocalories and blood pressure is measured in millimetres of mercury, both metric units that are not part of the SI.
Paper and sport Canada uses inch-based paper sizes such as letter (8.5 × 11 inches) and legal, rather than the A4 size used in most of the world. The federal government uses a combination of ISO sizes and the CAN 2-9.60M standard, whose P1 to P6 sizes are US paper sizes rounded to the nearest 5 mm. Stationery and photographic prints are sold in inch sizes.
Canadian football is played on a field measured in yards, 110 yards (100.6 metres) between the goal lines and 65 yards wide.
Construction and real estate