The square foot (ft²) is an imperial area unit equal to a square measuring one foot on each side, the standard measurement for home sizes, office space, and rental properties in the United States. Real estate listings in America almost always quote living space in square feet, making it one of the most practically relevant area units. One square foot equals exactly 0.0929 square meters.

The square inch (in²) is a small imperial area unit equal to a square measuring one inch on each side, commonly used in engineering specifications, screen size descriptions, and pressure measurements. Piston areas, material stress calculations, and electronic component sizes are frequently expressed in square inches. One square inch equals exactly 6.4516 square centimeters.