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A square inch (in2) is a standard unit of area in the imperial system, most commonly used in the United States.
To put it simply, it's the area of a square that measures one inch on each side.
For a larger comparison, it is equal to 1/144th of a square foot (ft2).
The square inch plays a vital role in one of the most commonly used pressure measurements: Pounds per Square Inch (PSI).
This unit is essential in everyday life, such as when inflating car tires or measuring water pressure in plumbing systems.
Simply put, PSI indicates the amount of force applied to a single square inch of area. This measurement is crucial for ensuring safety and optimal performance in various applications.
Since most of the world uses the metric system, it's essential to know key conversions.
For instance, one square inch is exactly 6.4516 square centimeters (cm2).
This conversion is essential for global fields like trade, scientific research, and manufacturing. As a real-world reference, a US postage stamp measures about one square inch.
While larger areas are measured in square feet or acres, the square inch remains the standard for specifying smaller surfaces.
It's commonly used in: