Metric system Summary

  • Last updated on November 10, 2022

Because the metric system is in common use in all major countries except the United States, American businesses are at a serious disadvantage in marketing a wide variety of products abroad.

There are two important components of the international metric system of weights and measures. The first is the fact that all measures are interrelated. Thus, any unit can be converted to others by simple operations involving powers of ten. The second is the establishment of standard values for the base units of each type of measurement. Thus, the unit of length is established as the distance light travels in a certain given amount of time. For mass, the base unit is established as the mass of a carefully guarded platinum-iridium cylinder located in Sevres, France.Metric system

In common usage, certain of the possible powers-of-ten values for the base units have become more common than others. For distance and size, for example, the meter, the centimeter (one-hundredth of a meter), the micrometer (one-millionth of a meter), and the kilometer (one thousand meters) are commonly used. For weight, the gram, the milligram (one-thousandth of a gram), and the kilogram (one thousand grams) are common. In some businesses, the metric ton is used. This represents is a megagram (one million grams).

Metric units of volume are based on the meter. Thus, a liter is a volume of one cubic decimeter and a kiloliter is a cubic meter. Areas are usually expressed in terms of square meters or square centimeters, but in some applications, as in agriculture, areas are given in terms of the unit “hectare,” which is a square 100 meters on a side, or 10,000 square meters.

Metrics in the United States

The U.S. government recognized the importance of adopting metric units as early as the mid-nineteenth century. To promote the metric system, Congress issued each state a set of standard metric units of weights and measures in 1866. In 1875, together with most other major countries of the world, the United States signed the Treaty of the Meter, an international agreement to use metric units in international matters, especially business. However, for more than one hundred years, American business has failed to realize fully the advantages of using the same units as adopted in other countries.

The U.S. government has made many attempts to promote a countrywide conversion from common (“English”) units to metric units, but with little success. A U.S. Metric Study was authorized in 1968, resulting in a recommendation from the National Bureau of Standards that the country be predominantly metric by 1981. Congress passed the Education Amendments Act of 1974Education Amendments Act of 1974, which asked schools to prepare their students for the metric system. In the next year, the Metric Conversion Act of 1975Metric Conversion Act of 1975 was passed and the U.S. Metric Board was created to coordinate a voluntary conversion. One of the first conversions occurred when the Bureau of Alcohol, Tobacco, and Firearms required wine and distilled spirits producers and importers to use metric bottles for wine and hard liquor. Metric speed limit signs began to appear, and distances on maps and road and trail markers were given in metric units. However, in 1982, President Ronald Reagan disbanded the U.S. Metric Board, and conversion activity ended. Metric speed limit signs were taken down. In 1991, President George H. W. Bush signed an executive order directing all federal agencies and executive departments to convert to the metric system.

Business and the Metric System

The problem for American business is that a complete conversion to metric units would be expensive. To satisfy the world market, it would not be enough to re-label a manufactured item; it must be redesigned to have metric dimensions. Currently, most manufactured items in America include a metric measurement on their labels, but it is given in parentheses and is usually not a round number–for instance, “net weight 20 oz. (566 g).” The world market would prefer to have the metric unit be the primary one on a label and to have the measure be a simple one to permit comparison pricing. For small-scale goods, this would require re-scaling the machinery that produces and packages the items.

Some American food and household products are sold in metric sizes. For example, soft drinks are offered in two- and three-liter bottles, and wine is almost universally sold in standard 750 milliliter bottles. However, other food items, such as meat and dairy products, have not been successfully converted.

In some commercial fields, there has been a curious hybrid conversion to metric units. For example, the tread of automobile tires is measured in millimeters, while the tires’ diameters are measured in inches. Otherwise, car manufacturers throughout the world use metric units for all parts, except for the lug bolts for wheels.

Although the American Automotive industry;metric systemautomobile manufacturing companies are using mostly metric units, manufacturers of other products have been reluctant to convert. Perhaps the most notable current case of a large, global business that has resisted metrification is the Boeing Company, which is still basing its design of airplanes on traditional units. For a small manufacturer, the advantage of a world market may not obviously warrant an expensive retooling of the plant. For computers, there has been a gradual conversion to metric-sized products. Digital versatile discs (DVDs) are 120 millimeters in diameter, but some computer components are still manufactured in traditional units, most conspicuously computer monitors.

Financial Measures

In finance, there is still a double standard for certain measurements. International production figures are usually given in metric units, such as metric tons; however, American statistics are often quoted in old units, such as bushels for wheat, barrels for oil, and pounds for certain other commodities. Unlike the case of Britain and various other traditionalist countries, U.S. currency has been decimal-based since the country began. However, only in 2001 did Wall Street cease to use the archaic fractional system of eighths in trading in stocks.

The gradual metrification of American business has proceeded very slowly, to the detriment of its potential global customers. However, with the ascent of European unity and prosperity, American business is realizing the importance of accelerating the conversion process.

Further Reading
  • Fenna, Donald. A Dictionary of Weights, Measures, and Units. Oxford, England: Oxford University Press, 2002. For a comprehensive account of the International Metric System and related systems of measurements, this fairly technical book is an excellent resource. Both the history of the system and its scientific foundations are covered.
  • Halsey, Frederick. The Metric Fallacy: An Investigation of the Claims Made for the Metric System and Especially of the Claim That Its Adoption Is Necessary in the Interest of Export Trade. 1919. Reprint. Whitefish, Mont.: Kessinger, 2008. Influential book that went to great lengths to demonstrate that the United States could get along without the metric system by showing how it had failed in other countries. The book’s twenty-five chapters examine the metric system in individual countries and regions, in different scientific fields, and in different economic systems. A fascinating historical document.
  • Law, Merry. Guide to International Measurement Systems: Practical Details About Metric, U.S. and Imperial Measures, with Paper, Clothing, Cooking, and Computer Measurements. Highland Park, N.J.: WorldVu, 2005. An examination of the metric system, with conversion guides.
  • U.S. National Archives and Records Administration. The United States and the Metric System: A Capsule History. Washington, D.C.: National Institute of Standards and Technology, 1992. Brief federal government report surveying the history of American efforts to adopt the metric system.
  • Whitelaw, Ian. A Measure of All Things: The Story of Man and Measurement. New York: St. Martin’s, 2007. Covers the history of measurement, including the metric system.

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