What is the United States Customary System?

The United States Customary System defines the units of measurement prevalent in the United States, which include the inch, foot, pound, and gallon. It’s similar to the imperial system, with a few distinct changes. 

The United States Customary System was standardized and adopted in 1832. 

The History of the United States Customary System

United States Customary System

Before the United States gained independence from Britain, residents used English measurements. These measurements included units like the yard, feet, and inches. While the UK formed the imperial system in 1824 based on English units, the United States wanted to differentiate itself.

Instead of adopting the popular metric or British imperial system, US leaders created the United States Customary System, abbreviated USCS or UCS. 

There have been a couple of legislation attempts to get the US to move toward the metric system, but they have yet to take hold. First, in 1866, Congress passed The Metric Act, which allowed the use of the metric system in commerce. Then, the Mendenhall Order of 1893 redefined the standards for length and mass based on metric units.

In recent times, the United States passed the Metric Conversion Act,  intended to slowly transition use from the customary system to the metric system. But because the act was voluntary, little changes have been made. 

United States Customary Units

The United States Customary system defines length, area, volume, and mass measurements. Here’s a look at the most common US customary units.

UnitAbbreviationMeasurement Type
Square Inchsq.in.area
Square Footsq.ft.area
Square Yardsq.yd.area
Square Milesq.mi.area
Cubic Inchcu. in.volume
Cubic footcu. ft.volume
Cubic yardcu. yd.volume

The United States Customary System vs. Metric System

The metric system features seven base units and uses prefixes that correlate to a power of ten. Because of this, conversions in the metric system are easy to perform and memorize. 

The United States Customary System doesn’t use the decimal system. Instead, every measurement constitutes a different amount making conversions hard. 

The easy conversions are a big reason the metric system reigns dominant. Another benefit of the metric system is that most of the world uses it, creating weight and measurement standards the US isn’t a part of.