Area

This article explains the meaning of area as a Physical quantity. The article Area (geometry) is more mathematical.

Area is a Quantity expressing the size of a region of space. Surface area refers to the summation of the areas of the exposed sides of an object.

Units

Square metre = SI derived unit

Are = 100 square metres

Hectare = 10,000 square metres

square kilometre = 1,000,000 square metres

square megametre = 10¹² square metres

Imperial units, as currently defined from the metre:

square foot (plural square feet) = 0.09290304 square metres.

square Yard = 9 square feet = 0.83612736 square metres

square Perch = 30.25 square yards = 25.2928526 square metres

Acre = 160 square perches or 43,560 square feet = 4046.8564224 square metres

square mile = 640 acres = 2.5899881103 square kilometres

Old European area units, still in used in some private matters (e.g. land sale advertisements)

square Fathom = 3.5967 square metres

Cadastral moon(acre) = 1600� square fathoms = 5755 square metres

The article Orders of magnitude links to lists of objects of comparable surface area.

Useful formulas

• Area of a Rectangle (and, in particular, a square): Length × width
• Area of a Triangle: ½ × Base × Height
• Area of a disk: π × r²
• Area of an Ellipse: π × a × b
• Area of a Sphere: 4 × π × r² = π × d²
• Total surface area of a right circular cylinder: 2 × π × r × (h + r)
• Lateral surface area of a right circular cylinder: 2 × π × r × h
• Total surface area of a Right circular cone: π × r × (l + r)
• Lateral surface area of a Right circular cone: π × r × l