The Origin of the Metric System | Smithsonian Institution (2024)

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What is the origin of the metric system? ›

On 7 April 1795, the metric system was formally defined in French law. It defined six new decimal units: The mètre, for length—defined as one ten-millionth of the distance between the North Pole and the Equator through Paris.

The metric system is a measurement system based on our decimal (base 10) number system. Other countries and all scientists and engineers use the metric system for measurement. Grams are used to measure mass or the weight of an object.

These measures had their origins in a variety of cultures -- Babylonian, Egyptian, Roman, Anglo-Saxon, and Norman French. The ancient "digit," "palm," "span," and "cubit" units of length slowly lost preference to the length units "inch," "foot," and "yard."

Whenever the discussion of switching unit systems arose in Congress, the passage of a bill favoring the metric system was thwarted by big businesses and American citizens who didn't want to go through the time-consuming and expensive hassle of changing the country's entire infrastructure.

The Weights and Measures Act was adopted in Britain in 1824, and the official British Imperial System began. This system lasted unit 1864 when the metric system was adopted in Britain. The United States uses the Imperial System similar to the one developed by the British, but it's their own version.

Imperial units

units of measurement of the British Imperial System, the traditional system of weights and measures used officially in Great Britain from 1824 until the adoption of the metric system beginning in 1965. The United States Customary System of weights and measures is derived from the British Imperial System.

The metric system is a decimal-based system of measurement originally based on the meter and kilogram, which were introduced by France in 1799. "Decimal-based" means all the units are based on powers of 10.

Conversions between metric system units are straightforward because the system is based on powers of ten. For example, meters, centimeters, and millimeters are all metric units of length. There are 10 millimeters in 1 centimeter and 100 centimeters in 1 meter.

The International System of Units is the modern metric system. It is based on the metre–kilogram–second–ampere (MKSA) system of units from early in the 20th century.

In other words, the French introduced not only national standards, but a system of standards. It survives today as the metric system.

What is the oldest form of measurement? ›

Often considered the first unit of measurement, the cubit was developed by the ancient Egyptians and was the length of the arm from the elbow to the tip of the middle finger (about 18 inches).

The United States Customary System of weights and measures is derived from the British Imperial System. Imperial units are now legally defined in metric terms.

The Metric Board was abolished in 1982 by President Ronald Reagan, largely on the suggestion of Frank Mankiewicz and Lyn Nofziger.

There are over 195 countries in the world, and all but three of them use the metric system. These three countries – Liberia, Myanmar, and the United States – insist on utilizing the outdated imperial system.

Post-1994 federal law also mandates most packaged consumer goods be labeled in both customary and metric units. The U.S. has fully adopted the SI unit for time, the second. The U.S. has a national policy to adopt the metric system. All U.S. agencies are required to adopt the metric system.

The METRIC SYSTEM was developed in France during the decade that followed the French Revolution (1790-1799); the terminology was all drawn from Greek or Latin. The SYSTÈME INTERNATIONAL (SI) is a 20th century refinement and extension of metric, formally approved in 1960; its terminology goes beyond Greek and Latin.

Public and private sector metric transition slowed at the same time that the very reasons for the United States to adopt the metric system -- the increasing competitiveness of other nations and the demands of global marketplaces -- made completing the conversion even more important.

In other words, the French introduced not only national standards, but a system of standards. It survives today as the metric system.

In 1975, Congress passed the Metric Conversion Act, which declared metric as the preferred system of the United States, and the U.S. Metric Board was created to implement the conversion. America began testing road signs in kilometers under President Jimmy Carter, who supported efforts to go metric.