Metric system use on the rise in the U.S.

International manufacturing is pushing use

Betty English pulls out handfuls of small plastic cubes when she teaches nutrition classes at the Richmond County Extension Office.


“It’s not bigger than your little fingernail,” said English, a family and consumer sciences county extension agent. “We use it because nobody knows what a gram looks like.”

Each yellow cube is the size of a gram of fat. The visual aid helps break down daily value on the nutrition facts labels, often given in metric weights and measures.

“It causes confusion. Packages have both ounces and grams,” English said.

April 7 is sometimes celebrated as Metric System Day, even in the U.S., where U.S. Customary Units reign.

The metric system, developed in France during the French Revolution, was officially adopted by the French government on April 7, 1795.

Use in the United States is more widespread than some would think.

Consumer products from shampoo to ice cream bear metric units. Consumers buy soda in 2-liter bottles without a second thought. Metric speed limit signs can be spotted in a handful of municipalities across the U.S. And it’s often the industry standard in science, engineering, manufacturing and medical fields, according to the U.S. Metric Association, founded in 1916 to promote the metric system in U.S. commerce and education.

Today, the nonprofit tracks metric system usage in the United States and publishes how-to guides for using the metric system correctly.

“People are using the metric system whether they know it or not,” said Christopher Spencer, the vice president of engineering at E-Z-Go in Augusta. “There are accepted standards so people can communicate.”

Since December, a petition asking the Obama administration to make the metric system the standard in the United States has attracted nearly 50,000 signatures.

“The United States is one of the few countries left in the world who still have not converted to using the Metric System as a standardized system of measurement. Instead of going along with what the rest of the world uses, we stubbornly still adhere to using the imprecise Imperial Unit – despite the fact that practically every other country that we interact with uses Metric,” says the petition on

In business, “metrication” is a natural consequence of the international nature of manufacturing and sales.

At both E-Z-Go and Club Car in Augusta, new vehicles are built to metric specifications.

“By the 1990s, all American cars were metric,” Spencer said. Because the industry shares suppliers with the auto industry, E-Z-Go now is, too. Only updates to older-generation vehicles are still done in inches.

“Both systems are taught in engineering schools and around the world,” Spencer said. As engineers, “these are the two systems. You better know both.”

It’s common to switch back and forth in some lines of work.

“A quarter-inch is not a good measure of a diamond,” said Steven Cranford, the owner of The Jeweler’s Bench in Martinez.

Jewelers learn to weigh diamonds by metric carat, and measure their size in millimeters.

“It’s a more accurate measure,” he said. “It needs to be right-on.”

The same holds true in baking, said Karie Collins of An Eventful Year Bakery in Aiken.

“You’re idea of a cup varies from someone else’s idea of a cup,” she said. “You need to stay consistent.”

Measuring ingredients by weight instead of volume solves that. Doing so with a kitchen scale that reads in both grams and ounces opens a cook up to recipes from around the world.

“A kitchen scale is the one thing I can’t live without,” Collins said. “Without it, you could have a completely different product when you go to bring someone your cake.”

Unless you’re an engineer or you grew up with the metric system, “a lot of people have to go through the conversions in their mind,” said Ben Cunningham, the manager of mechanical engineering at Club Car.

That might not always be the case, Cunningham said. His 12-year-old son is learning the metric system in school now.

“He’ll tell me measurements in centimeters,” he said. “His generation is metric-driven. They’ll all be using it before we know it.”

The U.S. Metric Association
Petition to make the Metric system the standard in the United States
A chronology of the metric system