The square inch equals 6.4516 square centimetres exactly. Used in US engineering, tile specifications, stamp areas and pressure conversion (PSI = pounds per square inch). A US letter-size sheet is 93.5 in².
Real-world: A US letter page is 93.5 in². A common US tile is 144 in² (1 ft²). Credit card ≈ 7.1 in².
Read full square inch reference →The square foot equals 929.03 square centimetres. It is the dominant unit for US home interior area and commercial space leasing. A 1500 ft² US home is typical suburban size (≈ 140 m²). Office space in the US is priced per ft² per year.
Real-world: A US suburban home is 1500–2500 ft². Manhattan office rents $60–120 per ft²/year. A small studio apartment is 400 ft².
Read full square foot reference →