Which system is often considered the opposite of the SI metric system?

The Customary system is often viewed as the opposite of the SI metric system because it is primarily used in the United States and is based on units such as gallons, pounds, and yards, which do not have a consistent factor for conversion like metric units do. The SI metric system, on the other hand, is based on units such as meters, liters, and grams, which are all interrelated through powers of ten, making it a decimal-based system.

This distinction is important in fields such as electrical work and construction, where precise measurements are crucial. Understanding the differences between these systems can help in properly interpreting specifications, blueprints, and codes that may utilize either unit system.