Do look now, for the metric system is coming.

For years now, there has been talk that the metric system will replace our traditional system of measurement. The time is now. Already, many American businesses are using both systems or even only the metric system. Metrics, however, will affect more than the business world. Soon the federal government will use the metric system in almost all of its dealings. Officials in local government will have to come to terms eventually with this different, although long-established, way to measure the world about us.

Our traditional measurement system is technically known as the "English system." Through colonization and dominance of world commerce during the 17th, 18th and 19th centuries, England established its system of weights and measures in many parts of the world, including the American colonies. Other countries had different measurement systems, however. The need for a single, worldwide measurement system was recognized early on, and in 1790 the metric system was created. At present, only three countries in the world do not, officially, use the metric system: Liberia, Myanam and the United States.

Many see the English system of measurement as an obstacle to American competitiveness and to the ability of the United States to improve its trade balances, especially as the U.S. begins to compete with such international trading cartels as the European Economic Community.

Concerned about the issue of world trade, the U.S. Congress in 1988 declared the metric system as a desired goal. Congress amended the Metric Conversion Act of 1975 (P.L. 94-168), declaring it to be national policy:

To designate the metric system of measurement as the preferred system; to require that each federal agency, by a date certain and to the extent economically feasible by the end of fiscal year 1992, use the metric system of measurement in its procurements, grants and other business related activities, except to the extent that such use is impractical or is likely to cause significant inefficiencies or loss of markets to U.S. firms...

The amendments required federal agencies to establish guidelines to carry out these policies. In addition, they required each agency to report annually to Congress on its actions to implement the metric system.

Federal agencies vary in their progress toward the goal of metric conversion. Generally, an agency will first mandate use of both systems and then phase in the sole use of metrics. Eventually, though, most federal agencies will be using the metric system. Local officials will have to use metrics when submitting grant proposals, engineering reports, and other material to federal agencies.

The modernized version of the metric system, as established by international agreement, is called the International System of Units, generally known as SI. Each quantity such as length (meter) or mass (gram) has its own unit of measurement, and no unit is used to express more than one quantity. The English system is more confusing: a pound can mean either force, as the number of pounds required to break a rope; or weight, as in a pound of sugar. An ounce can mean either volume, as in the number of ounces in a quart; or weight, as the number of ounces in a pound.

SI is a decimal-based measurement system, similar to our monetary system where units are related by a factor of 10. For each type of measurement the base unit remains the same and, if needed, a prefix is used. The most common prefixes are:

* milli -- one thousandth (1/1000);

* centi -- one hundredth (1/100); and

* kilo -- one thousand times (x1000).

The English system has a more complex structure, using different units and different factors for different amounts. For example, the terms "inch," "foot," and "mile" describe different lengths, and there are 12 inches in a foot and 5,280 feet in a mile. In contrast, the metric system uses only the term "meter" for length and, when describing much larger or smaller amounts, combines it with different prefixes.

Some everyday metric translations from the English system are:

* 1 gram equals about the weight of a paper clip

* 100 grams is a little less than 1/4 pound

* 250 grams is a little more than l/2 pound

* 1 kilogram is a little more than 2 pounds

* 1 meter is a little more than a yard

* 1 kilometer (1000 meters) is a little more than 1/2 mile

Temperature is recorded in Celsius under the metric system. Here are several useful comparisons:

* water freezes at 0 |degrees~ C rather than 32 |degrees~ F

* a "warm" winter day is 10 |degrees~ C rather than 50 |degrees~ F

* a mild spring day is 20 |degrees~ C rather than 68 |degrees~ F

* a "warm" summer day is 30 |degrees~ C rather than 86 |degrees~ F

* normal body temperature is 37 |degrees~ C rather than 98.6 |degrees~ F

* a heat wave is 40 |degrees~ C rather than 104 |degrees~ F

* water boils at 100 |degrees~ C rather than 212 |degrees~ F

Thinking metric is easier if you are just starting out; those of us who have grown up under the English system with its inches, feet, miles and pounds may feel as uncomfortable at the prospect of learning a new system as when we were forced to learn the computer. Learning the metric system is at once complex, tedious and downright scary. Fortunately, help exists: a single agency is coordinating all federal metric programs. An inexpensive set of conversion tables can also aid one's switch to the metric system.

To reach the federal program, write to:

Metric Program Office U.S. Department of Commerce Washington, DC 20230

The set of conversion tables may be purchased from:

Metric Programs 1000-10 Governors Park Winthrop, MA 02152

Donald Levitan, Suffolk University, SOM, 8 Ashburton Place, Boston, MA 02108-2770.