According to Joseph B. Reid, President Emeritus, Canadian Metric Association:
The use of the metric system for all purposes has been legal in Canada since 1873, but in fact only the scientific community used it until 1970 because its use was purely voluntary. It was only after the adoption of resolutions favoring metrication by associations of scientists, engineers, manufacturers and builders, that the government in January 1970 announced in a “white paper” that Canada would go metric. In 1971, the government appointed Metric Commission Canada with the mandate of planning and managing the conversion. The Commission adopted the target of converting by 1980 every aspect of national life. Some hundred sectorial committees, representing all aspects of the national life, were named and charged with drawing up plans. To coordinate it all, every plan was entered in a critical path database, with every plan ending at or before 1980. Unfortunately, there was little correlation between the forecasts of a plan and its results. Government services, electricity, gas, water, engineering, medicine, the grain trade, and commercial and industrial construction all converted in good order. But house construction has remained solidly wedded to feet and inches, despite the conversion of bricks, concrete blocks, and bituminous tiles. Although lumber is still in imperial sizes, plywood thicknesses are in millimetres.
In all Canadian schools, colleges and universities for the last 20 years SI (the International System of Units) has been taught, and nowhere is the imperial system formally taught. In contrast, at home parents speak often use the old, imperial system. The result is that children state their “weight” (mass) in pounds and their height in feet and inches, all the while not knowing how many ounces are in a pound or feet in a mile. On 1 April 1, 1975, Fahrenheit temperatures were replaced by Celsius, and an . (An opinion poll in 1989 found that 79% of the population now “thought” in Celsius.) In September, 1975, rain started to fall in millimetrers and snow in centimetrers. From 1 April 1,1976, wind speed, visibility, and atmospheric pressure have been in SI units, with the pressure in kilopascals. During the Labor Day weekend in 1977 every speed limit sign in the country was changed from mph to km/h. From the same time period, every new car sold had to have a speedometer that showed speed in km/h and distance in km. The distances on road signs were changed to kilometrers during the next few months. Gasoline pumps changed from imperial gallons to litrers in 1979. As for the quart, the pint, and the ounce, they are have been completely forgotten, although. Although, sometimes “miles per gallon” is mentioned, and cars are still rated in horsepower.
To summarize, the large industrial and governmental organizations function largely in metric units. The small and medium enterprises will convert when their competitors in the United States do so. In general, a person’s acceptance of metric is in direct proportion to his level of education, and the news media reflect this. Complete acceptance of the metric system by the general public will probably occur only after the older generations have died off.