Area Converter

Reviewed by the CalculatorHub team, edited by James Graham. NIST-defined conversion factors. Last verified 13 June 2026.

Area measurements come in a wide variety of units across metric and imperial systems, and conversions between them require careful use of squared-unit factors that differ from the corresponding linear conversions. For example, one foot equals 0.3048 metres, but one square foot equals 0.09290304 square metres (0.3048 squared), not simply 0.3048 square metres. This distinction trips up many quick mental conversions. In everyday use, square metres and square kilometres dominate in metric contexts for rooms and land areas respectively, while square feet are the standard for floor areas in the United States and Canada, and acres are commonly used for agricultural land in those countries and the United Kingdom. Scientific contexts may also use square centimetres or square millimetres for small areas, and square miles for very large geographic areas. The hectare, equal to 10,000 square metres or 2.471 acres, is widely used internationally for land areas despite not being an SI base unit. All conversion factors here are derived from the exact NIST-defined linear conversion factors: one acre equals exactly 4,046.8564224 square metres, and one square mile equals exactly 2,589,988.110336 square metres. This calculator converts among ten units simultaneously: square millimetres, square centimetres, square metres, square kilometres, hectares, square inches, square feet, square yards, acres, and square miles. Type any value to instantly update all others.