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 metre is the SI derived unit of area — the area of a square with 1 m sides. It is the standard unit for property floor area in Europe, Asia and most of the world. European apartments are sold by price per m², and urban land prices are quoted in €/m².
Real-world: A small European studio is 20–30 m². A 3-bedroom flat is typically 80–100 m². A tennis court is 260 m².
Read full square meter reference →